Since I like to be paid for what I do, I pay my software developers as well. I hope this doesn't come across harshly, it wasn't meant to sound like a snide remark—I completely respect if somebody uses free alternatives. After all, the respective companies didn't have to offer them if they didn't want to.
I think that funding development goes a long way towards the developers' interest in keeping the product around and improving it. Also, I want support if things go south. None of which I can demand or expect if I don't pay for it in the first place I reckon.