Because the world does not exist for the benefit of the rich and privileged; not simply the "rolling in Maserati" rich but those in a position to enact those gentrifying policies--who are overwhelmingly upper-income and capable of exerting more time to get what they want, have more money to apply to their causes, and generally are better-educated and able to execute.

The "selfish vote" amongst the privileged is indeed a problem. A lack of social responsibility and a refusal to understand that those unlike you must too be able to live are moral failings. They are wrong, and situations that increase the effectiveness and value of the selfish vote amongst people with privilege are undesirable.

No? Does it exist for the benefit of the poor then? -They sure keep voting for more wealth transfers and taxes on the rich, and they keep getting them too!

Note that I'm just an ordinary middle-class white person. I just wanted to point out that the world does not exist for any group's benefit. We're all just people, all just individuals here.

No. But we have ample historical evidence that huge wealth and privilege disparity does not lead to societal stability. The selfish vote of those rich and privileged seeks to increase this disparity. The selfish vote of the poor does not.