Blizzard is doing this for its what the people want.
the good exemple is hit rating, its not hard to see that people prefer hit rating over crit rating any day and thus the crit rating is starting to be underused, thats what blizzard wants to stop by simplifying the stats, they want less stats, but with all of them having its own goal and having it become less of a stat choosing to become maximum DPS.
this game has become way too mathematic to a point where even 1 point of a stat is considered better then 10 of another ! take haste for exemple. i completely agree with blizzard here, if people truly wants it to be mathematical, then why not just give 1 stat to everybody and make everybody the same, since its what the people seems to want. at that point people will see their errors and will be asking for the change back.
as for base stats, its a question of balance. they are simply trying to balance out things before cataclysm comes out. That should make people happy since it actually means that all classes will have equal chances in BGs and Arena's. the only ones who aren't ok with these changes are the ones who actually to only pawn the BGs like mad with their uber powered characters and are crying because they will lose that power.
for once, i see the base stat change as a great way to force people into choosing their race better !