It's not at all different from loving music written by drug addicts whom you wouldn't want as friends. Software developers are people too.
Out of all the music I listen to on purpose, maybe 20% is popular. I doubt the artists behind the other songs I listen to are multi-millionaires.
For example, many people against Facebook simply want to be in better control of their online identities, and have privacy. I am in this boat. I don't think Facebook is 'evil', or sharing my data with 3rd parties is a 'sin'; I just think society would be better off if privacy of this kind were more strongly controlled by individual choice, rather than the whim of a corporation.