YC is somewhat different, since all the investments we make are the same size. And, I'm biased, but I think we work pretty hard.
Interestingly, after crunching the data, this is not true.
In reality, companies who receive money from a larger, multi-stage fund actually raise follow-on financing at a higher rate than those that raise only from dedicated Seed VC firms who presumably care more as they're more invested (or that's what they'd like you to believe :)
While Chris Dixon (prior to joining Andreessen Horowitz) and others have championed the idea that large funds don't care and are just investing in seed rounds as a call option for future rounds, the data just doesn't support this contention.
We were as surprised as everyone else when we found this.
Full research brief we published on this here - http://www.cbinsights.com/blog/trends/seed-venture-capital-f...
Disclosure: I'm co-founder of the firm, CB Insights, that put this research together. We sell data to VCs, LPs, etc.
Right, so the problem isn't party rounds, so much as people not taking advantage of the fact that doing a party round allows them to go after smaller investors.
I think we work pretty hard.
Having never been through YC I have no direct evidence, but all the indirect evidence points in this direction, yes. ;-)