"He didn't come up with a new and interesting way to sell shit."
He identified an untapped location/population, and acted on it. How is that not finding a new way to "sell shit"?
I've had people try to sell me candy on the L before. I said, "no thanks" and that was that. I imagine this is the end result of 99.99999% of interactions between people on public transportation. (Someone stole my shoes once after he asked to read my newspaper and I gave it to him. That's the 0.000001% case :)
Besides, doing something because other people find it interesting is a terrible way to make life choices.
Incidentally, I love the NY subway for all its various distractions -- the breakdancers, the flashmobbers, and yes, even the panhandlers, because it's always interesting to observe how passengers react to them.