People are following the money - it's VERY hard to find backing for a 'change the world in 20 years' kind of company, but relatively easy to find it for a 'make $40m in 5 years' type of company.
I completely agree. I think people are following the path of least resistance to getting money, and this is the crux of what annoys me about the startup community. The goal is not transform an industry, at whatever cost, regardless of what anyone says, but get $40m as quickly as possible. Very few people have genuine convictions that they are hell bent on achieving, or at least it doesn't show.
Optimizing for a goal less likely to fail sounds like a good idea for young entrepreneurs that don't have any significant net worth or previous successes.
After they are financially setup for life, more seem to gravitate towards the really big, risky, transformative ideas.