Just because people make profit does not mean profit is their "only" goal. And like Paul Graham explained in his Y-combinator speech, there are certain services to humanity that simply would not work if they didn't make profit.
I think it's ridiculous to say that people like Steve Jobs are in it for profit. If Steve Jobs was after profit he would have been a highly successful wall street CEO or something. He does what he does out of personal ambition to improve the world. It's the same for 37signals and I would argue it's the same for Y-Combinator.
Well that, yes, and a bit of vanity I am sure.
37signals is really good at making you realize how these web companies might not be the best business to get into. Could there be a bubble slowing building that will eventually burst?
The unique part is 37Signals seems to concentrate mainly on PR. They're not the biggest or best, they just shout the loudest.
You seem like a great bloke from what I've seen of you so don't let low lifes get to you. Just ignore them.
All the best.