I have to disagree with you on this. Pixar has made quality stuff even after Disney bought them.
You already mentioned "Wall-E", but there is also "Ratatouille" which I thought was a very clever movie. "Up" is absolutely brilliant, and "Toy Story 3" should have won the Oscar for best picture. Let's not forget the recent "Inside Out" or "Coco", both very good and creative movies.
Yes, not everything has been a home run. "Brave" was good, but had potential to be great. "The Good Dinosaur" was a misfire, "Finding Dory" was good, but I thought it was an unnecessary sequel and I am not a fan of the "Cars" series.
Overall Pixar delivers, even after Disney bought them.
Alright, my mistake, I didn't quite catch on to that.
So have you seen "Incredibles 2" yet?