Installing it sucks. Once I got through that hurdle I liked it. However, I do think most people won't bother if the executable downloaded from the main website just doesn't run.
You can just pick the AppImage if you like Linux. No installation needed. If you are on Mac, then you just need to give permission to run the software, it is not a specific problem of TeXmacs, it happens because TeXmacs executable are not signed. There are many reason you can turn down a software. any software. The point is: to whom are you making a favour? :) TeXmacs is free and make you save a lot of time. So I would say it is worth to spend a bit of it learning to use it properly. To be effective it require you to unlearn some LaTeX habits. But again, it is up to you. What I think is unfair is to deduce from these features that it is not a useful piece of software.
