True, you probably won't get your butt kicked for getting in someone's face and calling them economically disadvantaged, but you won't win any new friends, either.
People get nervous when they're forced to describe someone as poor.
A couple of years ago, I was writing a series of stories about the DEA cracking down on Wichita Falls pharmacists for really silly violations of federal drug codes. One of the pharmacists, who's an extremely well-respected man in this community and someone I've personally found to be a pretty good guy, told me that the problem involved prescriptions brought in by poor people. But later on in the story, in a statement that wasn't in quotation marks, I used the word poor. And to tell you the truth, I promptly forgot about it. In my mind, it just wasn't a big deal.