"Organic vegetable growers, and farmers who put the welfare of their animals first are still part of the capitalist system" They are still reliant on massive subsidies to keep solvent and also comprise a very small minority.
"Plenty of capitalists go to lengths lengths to invest only in ethical companies. You can be a capitalist yet still choose to boycott enterprises you regard as unethical."
Plenty would suggest a majority. Totally erroneous I suspect. Similarly a capitalist boycotting unethical investments may well exist but again a minority.
You have to remember that another vital aspect of capitalism is competition( if it cannot be bought out, bankrupted or driven away by tariff barriers). Simplistically if competing on a "level playing field" lowest price wins. Competition will dictate price, location of manufacturing base, or raw materials and hence profitability. Altruistic concerns have scant chance of success in such an environment.
Some may say my interpretation is cynical, but for big business especially, it is realistic. That is the world we live in.
   It is a totally flawed system admittedly, but recent legislation has merely introduced further flaws and greater instabilities to the system. Government seems afraid to dictate to banks, the reverse seems to be the case.
    It really does make you wonder who really calls the shots.