It's a great point that these small launch vehicles will never be able to compete with larger vehicles like Falcon 9 on cost/kg. It does seem to me that launch factors besides costs (such as those described by others on this thread) leave room for small rocket players. I think a big question is how many players can exist in that small, dedicated launch market. It's also exciting to see how some of the small launch companies are exploring ways to differentiate themselves to carve out their own protectable segment of the market.