I agree and did follow up my statement with something similar:
"....just money, space and a decent work ethic if you want to have some success."
Again, my point is more that any Joe Shmoe can buy these products from the comfort of their home and join as competition. It's not a specialized growth industry like shale or something that takes training, specialized equipment plus lots of capital, time and work.
Now that's not to say that those of us who study the hobby, PLUS have capital, time, space and are self motivated won't be more successful than the average Joe Investor, but just that unsuccessful (and successful) new competition will keep profits lower than they were in the past and to take solace in the fact that for every sale you make with lower profits, you are probably preventing future competition from deciding to join the ranks. Isn't that a nice consolation prize? Eh, maybe not.