“Source available” is uncool, compared to “open source” or “Free Software”, in substance, not uncool as a term.

The non-ideological value of open source is exactly the commodification that the retreat to source available licensing seeks to end, along with downstream consequences of that commodification.

It is not a problem of terminology.

> Apparently marketing people who want to sell stuff under those new licenses think "source available" is uncool.

It's not that it's uncool, it's just not true and reflective of reality. There's a world of difference between a .zip on an FTP ("source available because GPL says it must be") and everything still happening in public on GitHub and everyone still being able to contribute if they want to. Both are technically "source available".

And yet a .zip on an FTP might be GPL-compliant whereas a GitHub repo isn't necessarily.

Exactly! But it's objectively a shit way of sharing code, there is no contributions possible, etc.

GPL or any OSS license doesn't require you to accept contributions. Your users are free to do anything with it except distribute derviative software under a different license, but you, the author, don't owe them anything except buildable and runnable (since v3) source code.