Nothing really brother. Just legality.
As far as all the hydro shop drama I seem to have started, I don't get where all the hate is coming from. It seems counter culture to me. Ya know, peace, love, and all that. When I was putting my system together, Green Hands had better pricing on an NFT setup and nutes, while Ohana had better prices on UFOs and grow tents (plus they had em in stock). Green Hands also hosted free classes, which were very helpful for me being totally new to the scene. Sure, Aaron tried to sell stuff at the classes, but he is trying to run a business and make a living after all... Can't condemn a man for that at all. And I highly doubt either Tom or Aron tried to rep a 2700k light as being blue, or a veg light... That's just sillyness.
Ohana is a good store too no doubt. I haven't had a bad experience at either store really, and I've spent quite a bit of time at each doing research and what not. I did notice they come from different schools of thought as far as their recommended methods though. Aron is an LED/coco/NFT guy and Christie (at Ohana) was recommending HPS/hydroton/ebb-n-flow. It's just different ways of doing the same thing really.