Because that wouldn't matter either. For a lot of people it STILL wouldn't be enough. It's NEVER enough. No matter what WotC does... a segment of populace is going to complain about it and say that WotC is mismanaged, horrible, unable to do the simplest things, yadda yadda yadda.
They could have said nothing about the docs. People would complain. So they give a reason WHY they are late. People are still complaining because it wasn't "enough". They could go ahead and add in the couple extra sentences you mentioned in your post, and people would then come back that THAT wasn't enough.
It's NEVER enough. Ever. Some people will find ANY reason to think WotC is horrible and constantly go on about it (here and elsewhere). It makes me wonder why any of these people even still bother to play the game in the first place when there are some many other companies out there that they probably think are the bees knees and they could play those games and have nothing but sunshine and daisies fly out of their books. I know I'd love it if all the people who can't help but complain about every single thing WotC does would finally just crap or get off the pot.