ycombinator makes sense for 2 kinds of people:
1) people who did not go to stanford/mit/etc. (if you went to those schools and you can't get a meeting with Sequoia, or anyone you want, you don't know what you are doing and should not be an entrepreneur.)
2) first time entrepreneurs who are age 24 and under and thus, do not know what they are doing as entrepreneurs. And thus need guidance.
for both of those subgroups of people, it makes a lot of sense.
ironically, you can only get into ycombinator if you went to stanford or other top university. hahaha... this will get refuted big time by the one or two cases where it is not true; but I'm sure it is largely true.