The company I'm with was founded literally right after September 11th, then funded in early 2002; basically at the nadir of the original tech bubble. But it had exactly the effect that you've described; there was no hurry to make a land grab, and far less pressure to try to get big quick to score a fast exit for the VCs. Starting in a down market gave us time to actually build something real and valuable and to build the company for the long haul instead of having to worry about the short term. It also let us hire an all-star team that would have been hard to assemble in boom years (and, incidentally, the most recent downturn has again made hiring easier for us).

The downside is that you'll get a comparatively lower valuation for the same amount of funding, meaning the founders will retain less of the company, but that company will probably have a higher probability of being worth something significant. So as a founder, it's still a net win.