That just doesn't compute. If they literally were about ethics > profits or maximizing good, they wouldn't be putting their time into a massively for-profit operation. Collecting large checks and internal perks galore. They'd be more attracted to a non-profit.

Contributing your (probably unskilled-at-what-you’re-doing ) labour directly at a non-profit is far less effective than working your skilled, high paying job and donating the money.

Yeah, that's probably true in a lot of cases.

I believe your argument classifies as a "no true scotsman"[1].

[1] https://en.wikipedia.org/wiki/No_true_Scotsman

Are there no ethical way to make a profit?

There are. This is certainly not to say that profits are automatically unethical or anything.

I just don't buy into the GP’s claim that they're putting ethics over profit.

Yes there are. Social enterprises do.

I don't believe that profits are more important than ethics, just that it is impossible to satisfy various opinions on what ethics is, while maximizing profit

That's correct. And I don't believe maximizing your profit should always go before thinking about what you do is ethical.