why didn't this happen at launch?

Is the next expansion going to be like this? Honestly, it's kind of awkward and just comes across as poor planning. I mean, this change totally makes sense, by why didn't this happen at launch?

I like a lot of things about Cata, but achievements feel really disorganized. I'm still not happy with the missing sell Wow Gold FoS for original Loremaster and Keymaster. (Getting the original Loremaster, by the way is a very different case than Exalted which at least builds on the same stuff.)

Things like, my characters having all sorts of Explorer stuff unlocked for lands they never visited, my main getting Surveying the Damage without actually surveying the damage, etc. So many achievements and FoS just don't make sense.