For users within large organizations, they're likely not able to use the software without approval from their legal department because it doesn't fall under any open source license.
Like I said, whether you care is really case dependent.
For more information on TimescaleDB licensing, check out this blog post: https://blog.timescale.com/blog/building-open-source-busines...
(Disclaimer/ fyi: I work at Timescale)
So some parts of Timescale are under actual Apache 2 and some parts are under a proprietary source available license. I'm not sure what the LOC of which is which, or how it's actually organized in your repo. I'll leave it up to your potential users to try to figure out which and disentangle what parts are actually open.
As I recall, AWS very publicly forked Elastic because of this very same type of confusion. The difference is that if AWS were going to fork your project, they'd just fork Postgres, which is the real open source software that you're benefitting from.
If I were building an developer focused analytics, monitoring, or data analysis product, I wouldn't do it on top of Timescale because some parts of your codebase most definitely prevent that through your license. But that's me.
