You want to fail as quickly as possible. Startups are like dating. If its not going to work out you want it to bomb quickly, so you don't waste your time and so you can move on to the next one...
Getting rejected by YC is not failure. YC has specific things they're looking for, and only so many resources to go around; getting rejected means that (a) you didn't match what they were looking for or (b) you didn't seem as promising as some of the other people who applied.
A friend of mine is a marathon runner who usually comes in under 3 hours. It turns out that there are enough people in that category that the Boston Marathon offers slots by lottery, and this year he wasn't one of them. Not getting a slot in the Boston Marathon doesn't mean you can't finish the race; it just means you have to find a different place to run.
Seems like the data is insufficient to talk about them dying, too: You've been going for 1.85 years, so even if the survival rate weren't particularly higher for year-old startups, the ones that have died so far would still be mostly younger than a year.
