Fully agree that pushing OSI is just posturing. After all, Amazon/Google/Facebook have made literal billions by commercializing open source software. I release stuff on MIT all the time (for things I'm okay with people poaching) but I'd argue the only "pure" OSS license is GPL, which comes with its own problems (and, as we all know, it infects everything it touches).

The problem with FSL is that it hasn't been tested in the courts yet (afaik), so it's a bit of a gamble to think it'll just "work" if some asshole does try to clone your repo and sell your work. Maybe it's a decent gamble for a funded startup with in-house counsel, but if you're just one guy, imo keep stuff you want to sell closed-source, it's not that big of a deal. We've been doing just that since the 70s.