

To answer the question, no - you’re not the only one. People have written and talked about this extensively.
Personally, I think there’s a lot more nuance to the answer. Also a lot has been written about this.
You mention “communities that are security conscious”. I’m not sure in which ways you feel this practice to be less secure than alternatives. I tend to be pretty security conscious, to the point of sometimes being annoying to my team mates. I still use this installation method a lot where it makes sense, without too much worry. I also skip it other times.
Without knowing a bit more about your specific worries and for what kinds of threat you feel this technique is bad, it’s difficult to respond specifically.
Feel is fine, and if you’re uncomfortable with something, the answer is generally to either avoid it (by reading the script and executing the relevant commands yourself, or by skipping using this software altogether, for instance), or to understand why you’re uncomfortable and rationally assess whether that feeling is based on reality or imagination - or to which degree of each.
As usual, the real answer is - it depends.
It’s not just that. I’m a techie. I’ve been in the industry for decades. I know my way around computer very well.
I want to like Jellyfin and I want to ditch Plex (even though I have a lifetime license) because of what it has become and where it’s headed.
That said, the other day my Plex server had some issues that took me a while to figure out. Since when it failed I just wanted to watch an episode of a series and relax, I once again fired up the JF client. I couldn’t get seek to work, I had to manually find and download subtitles (that’s not always the case but when it is, it’s pretty annoying), and ultimately I couldn’t watch my series at all as playback would randomly stop, the player would close and I’d be back at the menu, without the position having been recorded and with no way to fast-forward as seek didn’t work at all.
I ended up spending 15min figuring out what was wrong and fixing Plex, then watched my series undisturbed.
Like I said, I want to drop Plex for JF, but in the 3 years or so that I’ve been running both, every time I fire up JF I end up running back to Plex as I just want to sit back and watch a bloody series or movie.