Hrm, I dunno. It seems like a pretty good deal for the person whose rent is controlled. I can hardly imagine that they'd (on average) be better off if they were forced to move elsewhere, or forced to pay more. It seems like what you might be observing is a correlated effect. That is, people who are so dependent on rent control must have a certain amount of fragility in their financial situation. Older people in financially tenuous positions are understandably reluctant to venture forth and take risks, both because we become less neuroplastic as we get older in general, and because poverty is not conducive to risk-taking.

Now, whether rent control is good for society as a whole, I think that's a very different question with quite the opposite answer.