I agree with you as they have no real way to prove such a theory. They just dream it up and pass it on as settled science.
I caught on to their far out conclusions when watching a T-Rex show where they said the monster had an outstanding ability to smell. This was based on a rather large olfactory cavity. For an animal that primitive it is likely such a large cavity could be proportionately primitive, meaning size has nothing to do with how well it can smell anything.
Another factor: we know that modern humans have different ear wax based largely along racial makeup. Do we have any ideas about Neanderthal ear wax? Because that would tend to mitigate the susceptibility to ear infection. Certainly there’s no evidence in the fossil record.
I suspect that T Rex did have a powerful nose, and the legs to travel long distances to scavange dead critters. In fact I suspect he may have been more scavanger than a hunter killer. Their brains may have been more primitive than ours, but they had been in the process of evolving for over 100 million years, so I suspect their nasal cavities were quite well developed.
So far as scientists earning money doing research. Without that research, museums would not have their interesting exhibits which children and parents enjoy so much. Why are scientists whose work entertains them of less value than the athletes whose sports work also entertains them while many athletes get far greater pay?