Its truly amazing how the human mind can so glibly dismiss obvious evidence when it contradicts pre-established theories. The Therapods were clearly warm-blooded and some of them, at least had feathers. If they didn't give rise to birds themselves, birds and theropods had a very close common ancestor.
The idea of a 40 foot tall T. rex running around in a chicken suit is an amusing picture, however.
It's probably a good thing that they are extinct. Can you imagine the problems cleaning your car of dinosaur crap after it sat in the sun all day. Whew!