Steve Ballmer nailed it when he said GPL is a cancer. No professional
programmer wants to open source anything, but once one competitor does
it, he must follow suit to stay competitive.
Firstly your appeal to authority , and then using Steve Ballmer as your authority is perhaps not the best way to start.
Secondly you say that "no professional programmer" - but the statement is false. For starters it's a sweeping generalization which is trivial to show is untrue for at least 1 programmer.
Thirdly the existence of Open Source alternatuve does not make a product uncompetitive. You need look no further than Windows to see that's true. Indeed if we has to list all the commercial software that exists with an Ooen Source clone, we'd be here all day. I'd also argue that Joe public doesn't even know what open source is, much less factors it into a buying decision.
If you are building tools for programmers (already a tiny niche target market) then you need a hook other than Open Source anyway, cause programmers are a terrible target market.
I say this as someone who builds tools for programmers, and who sells commercial into a space that contains Open Source alternatives. And I do ok.
Instead of getting people to try and come up with an argument that wasn't made, the argument could have just been made. But I'm sure it is a very bad argument, or else there wouldn't be that embarrassment to try.
1. Build a piece of software that actually solves one or more problems.
2. Keep ownership private and limited. Once you're publicly traded, long term planning becomes impossible and "line must go up" becomes the reigning false god.
3. Sell a perpetual commercial license to the version-at-purchase, and offer subscription for updates after purchase. On cancellation, stop providing updates but do not disable that customer's last working version.
4. Optionally, dual license under a free license that prevents competitors from eating your lunch (usually latest GPL or AGPL, depending on context).
If you're implementing the above items, it's absolutely possible to run a profitable company.
You can fight this with dual-class ownership. Google and Meta can do whatever they want because nobody can change their board.
They're still motivated to care about share price because they pay their employees in shares, but you're going to have to get the money to pay employees from somewhere.