I for one am glad that nothing got restricted, nothing got unrestricted, and Portal was not added.
Third, this issue of Portal is something that baffles me. I understand the theoretical appeal in saying that EVERY card in Magic is legal, but I think adding Portal is a bad idea. First, the vast majority of the cards are terrible. Second, the cards that are good are watered down version of cards we already have, like Imperial Seal. Why are we clamoring for a sorcery speed Vamp Tutor when Vamp Tutor itself is not all that hot? The mania for completeness seems to be the only good reason why. Third, and most importantly, adding Portal and then restricting the necessary cards, as bad as it is Imperial Seal is still restriction worthy, would simply compound the critical mass problem. If Portal was legal and Imperial Seal restricted what does that do, really? It means that there are 3 cheap full tutor effects in Vintage, negating the fact that each individual card, Demonic Tutor, Vampiric Tutor, and Imperial Seal, are restricted. We certainly do not need two Vamp Tutors, two Mystical Tutors, and so on. So while it would be cool to play with Zodiac Dragon and Jungle Lion, overall adding Portal is such a hassle. Final thought on the issue: how much of an administrative nightmare would it be to have three sets in which every card is essentially totally errated and having to restrict cards automatically with the introduction of the sets? Too many problems, not enough incentives....keep Portal out.
1. The vast majority of cards are terrible
The vast majority of cards in Portal and starter are low in power level although this does not make them terrible cards as many have excellent flavour and great art.
Assuming you are only talking about the power level of the cards, are you suggesting that sets should only be allowed into Type I if the vast majority of cards in them are not of a relatively low power level? Surely Legions, Prophecy, Homelands, The Dark and many other sets would be excluded under this principle.
2.The critical mass argument
The critical mass argument you present says that we should not allow the sets into Type I because there are good cards that are very similar to existing good cards. Thus you suggest that sets that contain cards similar to existing cards should not be allowed in Type I.
So no sets with the vast majority of cards in them weak by Type I standards, no sets with good cards that are similar to existing cards should be added to Type I. Oh, Brave New World...
3. Hassle/Admin
All that is required is an announcement, ideally with the B&r list for clarity (although this is not strictly speaking necessary) and to be very very safe the addition of Imperial Seal to the B & R list.
The Oracle listings already include Portal and Starter so there is no further work to be done on card interpretation. In addition a retarded chimp can understand the working of Starter and Portal cards, suggesting that people would have to consult the Oracle list in order to use these cards is a bit daft, they were specifically designed to be easy to understand. There are a huge number of Type I cards that you would have zero chance of understanding properly if you read just the card without knowing the Oracle wording and pages of rulings. (Helm of Obedience anyone?)
Perhaps you are taking of Horsemanship? I believe players who can handle Flanking, Phasing, Double Strike, Trample, Banding and Rampage can figure it out. That combined with the fact that no Horseman will see the light of day in serious competition.
Type I IS the format where every card is allowed unless there is a good reason not to. Frankly there is no good reason not to allow these cards.