When you say "They" do you mean virtually every single person that uses cannabis? Because that's who wants it legalized. Scotts Miracle-Gro sells affordable products to millions of satisfied customers. They don't rip people off selling bottles of diluted epsom salts for $25 or some pollen chucker getting $50 for a seed. They are no more or less ethical than a good portion of all companies and individuals making money in the cannabis growing supply space.
I only use one of their products but I have absolutely no issue with them as a company. It's a well run company ran by talented people that know what they're doing.
I have no problem using their products. This is as effective as Clonex for 1/4 the price.