Democrats need the votes of poor people and that's where a lot of the Democratic base comes from. Democrats can't going around hating poor people, that's not going to win votes.
You don't go around hating them, but you can't go around promising to uplift them either. Most people are extremely resentful toward them because of muh taxes and teh Welfarezz!!!11
Democrats only win when they have coalition of voters, which includes the poor. Across the board, Democrats need to reach voters in need of jobs and economic growth.