The other option of course is to invest large amounts into startups that are well on their way, but Sequoia and AH have a corner on that market. And now YC wants to play there as well, with their larger fund.
So there's no oxygen left for a lot of the VC firms in the valley. There's no shortage of money looking for VC funds, as returns are low in general asset classes. So you have this imbalanced situation, where dinky startups get incredible valuations, and there are too few genuine investment opportunities to go around. SC are one of the marquee victims, but other walking dead abound, though they dress snappy so it's hard to tell they're really dead.