If you are playing against any artifact deck with prison components (i.e. 3Sphere, Tangle Wire, Smokestack) and your opening hand doesn't contain either a FoW or your own Workshop, the only realistic way to combat the frequent play of turn 1 Workshop-->Trinisphere is Wasteland, so at least its effect is symmetrical, and not distorted by their reusable Black Lotus.  If Wasteland becomes restricted, a blue player is forced to mulligan into a hand of Force of Will + blue card or risk being locked out of the game before they even get to lay a land, and, if you're not playing blue (or your own Workshops) then why even bother? FCG can't be paying 3 to cast their goblin lackeys...and not to mention combo, which just scoopes to first turn 3sphere.
Restricting Wasteland would only further distort the metagame towards Workshop decks, and would almost immediately warrant the restriction of 'Shop as well.

@Firebird:  Thanks for the help.  I just have one thing to ask about DoJ...you mentioned the difficulty in getting WW to cast it, but especially in a deck that revolves around win conditions that aren't spells (hence the standstill), wouldn't the U/W/r version only need to have W open because of Decree's ability to cycle for soldiers? And is it that difficult to keep a single Tundra on the board to make this happen?

I've recently picked up Standstill and have been playing it for about a month or so, alternating between U/W/r and U/R, using fairly standard versions of each.   As of yet I have not played a single pseudo-mirror match (i.e. U/W/r vs. U/R or vice-versa).  I was wondering if anyone had any input as to which build has the edge in this type of matchup.  Thanks for the help!