In college there were groups that would throw a thanksgiving dinner for students that couldn't make it home to be with family. Were they wrong or elitist or uncaring? It is a common group tradition in the US to throw thanksgiving for some group you belong to. Besides the fact even a CEO of a startup cannot afford meals for every homeless person or just everyone off the street, it makes it no less nice if it happens to be for a social group and maybe some business is done. If the Churches[1] in SF weren't serving a thanksgiving dinner for the homeless then I am surprised.

1) Churches generally do this regardless of belief of the homeless. It is about the beliefs of the church not the served.