A site where you vote on links? Why I could build that myself. An SMS interface to PayPal? Why I could build that myself. A website that gives away money to startup founders? Why I could build that myself!
If there was much more money from investors or the partners, would YC fund any more startups then it does? I have to admit, I know virtually nothing about how YC works, but it doesn't sound like it's all that capital intensive. And the cycle shouldn't be that long either.
I'd have to add that YC isn't exactly your average startup though, and the founders putting their own money in sends a much stronger message of dedication to potential participants.
In any case, I'll take your word for it as you definitely know Paul better than I do. ;)