Is there any risk of Bash ever going away? It seems like it's the de facto shell. I remember considering whether or not I should learn Perl at one point. It didn't even feel like a choice with Bash. Trendy shells seem like they have no choice but to support it too.
I feel like what usually makes me reach for something beyond Bash is really a matter of wanting or needing some dependency that wasn't written in it for whatever reason. Usually this happens right at the point where the script/utility starts to turn into a library/program, so it's trivial to just transpose the control flow into whatever language is required at that point and go from there. This of course raises the type of concern you mentioned about Ruby, but at that point it's hopefully worth the trouble to address.
I feel like what usually makes me reach for something beyond Bash is really a matter of wanting or needing some dependency that wasn't written in it for whatever reason. Usually this happens right at the point where the script/utility starts to turn into a library/program, so it's trivial to just transpose the control flow into whatever language is required at that point and go from there. This of course raises the type of concern you mentioned about Ruby, but at that point it's hopefully worth the trouble to address.