I guess I haven't been around enough small startups (fewer than 100 people) because I hardly get the sense that people are haphazardly spinning hadoop clusters.

I guess I haven't been around enough small startups (fewer than 100 people) because I hardly get the sense that people are haphazardly spinning hadoop clusters. People generally pick the right tools for the right jobs. This is particularly true in the datawarehousing world. That being said I can see problems where people pick hadoop without knowing how it's going to integrate into their systems 1-3 years down the road. Particularly with cloud computing these days, you can easily bring large complex systems online with little effort. It's cool and scary at the same time.