It is rational behavior to protect your investments and way of life in this manner. I think it's often short-term rationalization, and acting on bad information, but people are acting in a rational manner given their information and circumstances. Given that, it's probably good to address the base of that rationalization, rather than expect them to behave differently. I.e. give them more information that makes their prior behavior no longer the clearly beneficial choice for them, if such information exists. Play upon their sense of justice and ideals (such as ChuckMcM is). etc.
Nonsense. I don't live in San Fran, I do live in a city whose character has changed. I don't mind that people saw the cool inner city and wanted to share. I do mind that developer put up cheap high-rises with shit sound insulation, and then waged war on music venues, getting most of them shut down. I do mind that rents escalate massively year-on-year so that the hitherto broad range of inhabitants have steadily whittled down to a richer and richer (and frankly less interesting) rump. I do mind that many landlords would apparently rather see an empty shopfront than an interesting store that's no longer viable because apparently the thing to do is year-on-year 30% rent rises.
A.k.a they don't want to share.