Which parallel programming startups are you referring to? Sure, the established companies are adapting their exisiting tools to address the new multicore processors but I am not aware of any new parallel programming tools startups that failed. Most of the multicore processor startups are still around. Tilera, Ambric, Pico, etc... are still hanging in there. Pico is doing great. Israel's Plurality is just now beginning to get recognition for its self-balancing 64 to 256-core hypercore chip.
My point is that there are very few new multicore startups and I think that the reason is not that too many of them failed in the past but that only a few have had anything really interesting or disruptive to offer. It remains that there is a big problem that needs to be solved right now and whoever solves it will grab a lion share of the CPU market in this century.