at what point do look around and say I have earned enough profits so I need to slow down or even shutdown my operations or someone is going to call me "evil"?
At no point you should stop what you're doing just because you're earning enough. You should stop what you're doing when this that you're doing can only be properly described by the words "sociopathy" and/or "psychopathy". Given that, you can however certainly continue doing all the other non-sociopathic, non-psychopatic stuff you've doing that earns you huge and ever increasing profits. Those are fine.