Scott Kirsner writes: The optimistic view is to see Massachusetts as one of the world’s great R&D labs. But I often find myself wondering whether being the R&D lab to the world is enough. My worry is we aren’t producing new “pillar’’ companies, which employ thousands of workers, recruit talent to state, and set the direction for their industries. If all you do is grow guppies, it’s hard for people to regard you as anything other than a small pond.