I don't believe it's "as soon as their business allows them", but as soon as the owners decide they don't care. You can have a company that runs at low margins and does some good if that's what the founder wanted. The problem is that the founder will eventually die, and someone else will own the company. That could be due to going public, taking on other private investors, or just leaving the company to family. New owners are so often driven by money that they will abandon being nice or supporting a cause.
Lets all follow Mark Cuban's pharmacy company as an example. He's offering drugs at a 15 percent markup. Great cause - making meds affordable to people. It will eventually be co-opted by greed, but lets see how long it takes and who actually gets greedy.
They can't change, as nearly every other (successful) company can't. They're built for profit, but human related values such as morals, honesty, sincerity, and generally being good to others etc. have no place in business: those are obstacles that soon or later must be removed to maximize profits. I expect pretty much every company to act in a benevolent way when they're young and still in need to establish a good public image, but as soon as their business allows them, they become evil, I mean not in a superhero comic baddie way ("muhaha! I'll conquer the world"), but rather in a very cold "we don't need to be nice anymore" way. It's just how they're created, and the environment they "live" in that shapes them: if you dwell in a sea full of sharks, you better learn to behave as a shark, especially if being a shark guarantees more rights and less obligations than most humans.