Tauri's pitch is something like, "Electron, but lighter weight and more secure," not "written in Rust." If you're skeptical of the value in that, hey, so am I.

I'll cite my own experience:

I learned Rust because I needed a modern systems language in my toolbox. I specifically wanted something that could be used to write firmware. So I chose Rust over alternatives like Go or D, because I couldn't tolerate a garbage collector with those requirements. Trendiness had nothing to do with it; in fact, I was hesitant to pick it up because I was worried it wouldn't have staying power. (Having taken the plunge, I have no regrets.)