I'd much rather see Disney focus on building additional land and increasing capacity than replacing existing attractions. I'm no particular fan of Dinorama but why not have that and whatever additional attractions could be build on the myriad of undeveloped land in DAK. TDO should focus on making increasing the total attractions at DAK, extending the hours and adding a nighttime show. Then they can replace subpar attractions.
I'd agree in most other situations, if the attraction they were replacing was actually worthwhile. For example, i'm pretty much ok with Carsland replacing the backlot tour as well as LMA because I'm really not a fan of either existing attractions but would really see the value of Cars. On the other hand, I don't really appreciate replacing already good rides with rides that either aren't much (if any) better or meet and greets (replacing Toad with Pooh, 20k Leagues with Mermaid, Imagination with the current ride, Horizons with Space, WOM with TT, etc etc).
Don't get me wrong, I think expansion should definitely happen as well, and i'd probably agree that they should perhaps build stuff before gutting Dinorama. Specifically anything involving Lion King, Jungle Book, Up, Emperor's New Groove, Indiana Jones, etc). But the thing about Dinorama is that it's (to me) a tacky ugly blight on an otherwise gorgeous park. It sticks out like a sore thumb and really just screams cheap. It's not only taking up precious real estate that could be used for a GOOD attraction, it really clashes badly with the rest of the park (not in that cool way that Magic Kingdom pulled off, it's just ugly overall). I expect to see this kind of garbage in Kissimmee, not inside Disney World. If the couple of carnival rides were replaced by a single massive flume ride of classic Epcot caliber, I see little reason to complain. Having a multi-floor journey across the river of time through various ages of prehistoric life coupled with immensely detailed show scenes and tons of animatronic extinct animals would be incredible. Throw in 2-3 mild drops (ala POTC or Maelstrom) to give it a slight thrill factor for the kiddies as well as a respectable amount of classic Disney quality show scenes and you've got a match made in heaven IMO.
And in the meantime, expand Countdown to Extinction's show building and length to give it the proper boost it needs to not just be an Indiana Jones lite. It deserves it, I can definitely see its value underneath all of its flaws.