In this case though, TimescaleDB has blog posts that describe the license in very plain language, and provide clear examples of what you can and can't do - you can basically do anything except provide it as a service. No need to "wing it".
For those people who use Timescale and really like it, and are willing to read and understand this license and then use it, I say "Great!" But in general I find license proliferation to be undesirable and would generally encourage organizations to use standard licenses.
I do think there is a need for a TSL-like license though, and I think the solution is a new type of widely accepted and understood license, rather than individual companies inventing their own TSL-like licenses.
I have no idea how that could actually come to be though.
People can't start using licenses if you don't first write them.
Of course I could just "wing it", read through it, and work off my layman's interpretation and hope for the best. Or.. I could choose to stick to well understood and well known licenses that already exist.