Jar: could you clarify what you mean by your statement (paraphrasing) that "shift in design to focus on creatures is decreasing strategic diversity"?
Specifically:
1.) what was the previous focus on design?
2.) how did it encourage strategic diversity in a way that a focus on creatures, creature abilities and combat does not?
1). You can look at the game as having 2 major phases of design(With some anomalies, such as Combo Winter). The first phase, which I consider to have begun during Alpha and ended at around Morningtide, had noticeably more powerful spells, many of which did not focus on creatures, and weaker creatures. This led to an ideal arrangement of Archetypes in all Constructed formats, even Standard, that had a mix of Aggro, Aggro-Control, Tapout Control, Draw-Go Control, Combo, Combo-Control, Midrange, and others. This suite of Archetypes is the ideal form of the Strategic Diversity that I support. One of the good things about Vintage is that it is by far the most strategically diverse format, and is the last place where Prison is truly competitive. Creatures were still a fundamental part of the game during this period, and I consider it the better of the two phases, with the Absolute Golden Age of Design being Tempest Block. I consider Time Spiral Block to be the last truly "pure" block.
The second phase, which continues today, is defined by severe creature Power Creep, and a larger focus on creatures in Constructed formats. As this era goes on, Wotc's pet constructed formats (Standard and Extended, the latter of which has been replaced by Modern) have been more and more defined by Zac Hill's ideas of archetypes (for reference, read the articles I mentioned in the above post). This leads to far less Strategically Diverse metagames than in the past, for the simple reason that Zac Hill's archetypes commonly existed in the first phase of Magic's History, but alongside even more archetypes. In Standard today, there is no combo (And the few combo decks in recent Standard seasons have all been creature-reliant), and not enough Control. The least they could do is reprint Counterspell for Modern. Meanwhile, Standard and Modern are dominated by Aggro and Midrange. There have been some exceptions, yes, but overall the game has become less diverse in the way of Archetypes.
2). Putting too much focus on creatures takes away from Control and non-creature based Combo. Making large, undercosted creatures has recently made Goodstuff Midrange Decks the best archetype in Standard and Modern by default. Aggro is given enough support to be competitive, while Tapout Control barely gets enough support to make it seem like Wotc cares. Draw-go Control is almost nonexistent.
Theros Block is the culmination of the Second Phase of Magic. While previously during this phase, Instants and sorceries became tacked onto creatures as ETB abilities, the abilities of global enchantments, many of which were designed previously, have been attached to creatures.
There can still be good sets for all formats in the Second Phase, WorldWake coming to mind. However, this involves taking a step back from where Theros has led us.
@JarofFortune: imho creatures are the main type of spells in magic, specially in limited. I agree that is good to allow other decks for the sake of diversity, but there can't be a mental mistep, abrupt decay or swan song every set (although it would be nice to have at least few every block, unless there is some kind of flavour bias). Now we would have conspiracy in little more than a month and we are probably having some eternal playables. There you can expect some "broken" cards, but it's hard to create vintage playable cards after 20 years, specially if you don't want to break other formats.
I agree with your first statement. Whenever someone starts playing magic, it is always with creatures. Limited formats have always relied on creatures. However, If we look at sets from the first phase of Magic, there
can be a good non creature spell or utility land in every set. This is a reason for the supremacy of the Rath cycle over all other blocks. Each set was packed with cards playable in every format, and lots of great design. I can give countless examples: Volrath's Shapeshifter, Licids, Aluren, Dream halls, Humility, Volrath's Stonghold, City of traitors, Wasteland, Lotus Petal, Flame Wave, Intuition, Ghost Town, Slivers, Limited resources, Curiosity, Living Death, Recuring Nightmare, Grave Pact, anything with Buyback, and more. Vintage cards can be printed very easily without breaking other formats. This would be even more true if Wizards would print some good policing cards for Modern. If they did this, the ban list could be much smaller than it already is, and more powerful cards could be printed in Standard.
@JarofFortune: imho creatures are the main type of spells in magic, specially in limited. I agree that is good to allow other decks for the sake of diversity, but there can't be a mental mistep, abrupt decay or swan song every set (although it would be nice to have at least few every block, unless there is some kind of flavour bias). Now we would have conspiracy in little more than a month and we are probably having some eternal playables. There you can expect some "broken" cards, but it's hard to create vintage playable cards after 20 years, specially if you don't want to break other formats.
Its been a while since I read the disturbing articles he presented, but I think the gist of his issue isn't that creature types are the main type of spell in magic, it is that the design ideal in those articles would make it so that creatures and creature based interactions would be the only type of spells created going forward.
This means you will never get to see innovations like storm, flashback, threshold or pitch costs again, where something is made relevant outside the red zone. And even if there is, it is forcibly tied to it like only printing moment's peace/artful dodge and no coffin purge/deep analysis or only mystic enforcer/nimble mongoose and no cabal ritual/cephalid coliseum. Instead we get things like level up and monstrous. Instead of combo decks like Tog, Trix or Dragonstorm you get combo decks like equipping runecatcher's pike to an invisible stalker.
Also, if I remember right he said something to the effect that cards like force spike and mana leak were way too powerful for standard. It is kind of sad to me since the last time I thought standard was fun was when 7th edition was legal, due to the effect force spike had on the format. It made everyone play smarter, and build better decks. Was it powerful? Yes. Was it format warping? Yes. Was that a bad thing? No.
I don't think that pushing the envelope for creatures is a bad thing, but intentionally reversing the power level between spells and creatures instead of trying to even them out is bad design.
Spot on. This sums up my opinion very nicely.