Me, I just don't care about proprietary software. It's not "evil" or "immoral," it just doesn't matter. I think that Open Source can do better, and I'm willing to put my money where my mouth is by working on Open Source, but it's not a crusade – it's just a superior way of working together and generating code.
Torvalds, Linus (2007-03-19). The Torvalds Transcript: Why I 'Absolutely Love' GPL Version 2