Well, I think a lot of people just want things to update and change. You're forgetting that Universal has been pretty dead for a very long time, it's only getting the love it deserves now. Also, not everyone wants ALL of those rides to change or be replaced.
Speaking for myself, Rockit isn't going anywhere but it should. To me, Rockit is a huge, ugly red symbol of Universal's dark days. Shrek needs to go because it takes up a lot of place and it's just not as entertaining as it once was. ET needs some love and I'm not sure how anyone can deny that. I honestly vote for it to be replaced, but eh. I was also never a fan of T2. I think most of us just love the parks and want it to be the best it can be. You really think that KidZone, Beetlejuice, Disaster, Fear Factor, Barney, Toon Lagoon, River Adventure and JP as a whole doesn't either need to be replaced or updated?
I don't think it's complaining to complain, I think we want the park to change for the better and that means getting rid of the dusty, unloved attractions. No one is going to stop going to Universal because KidZone is a mess, because 90% of the park is great, it's the other 10% that needs a bit of work. Nothing is perfect.