Yeah, it's too shabby for you, but many someones grew up there an have emotional ties to the place. Not everyone wants to, or can, live in a nice suburb, on 1/4 acre of lawn.
Also, I bet that in most of these cases, they're not being told that the building is being updated, that the state will pay for at least some of their interrim living inconvenience, and that they're guaranteed an appartment when the reno is done, at marginal cost. No, they're almost certainly being booted out with token compensation in order that more expensive appartments can be built which the old residents have absolutely no chance of affording.