With love: I always felt like fish and even zsh are kind of beautiful OCD-induced bouts of counter productivity in the same vain as Dvorak keyboard layouts and Plan 9. We can't handle things being messy and imperfect so we solve it by building our own parallel universes. What do you do when you have to use a computer without your customization? Perfect is the enemy of good, worse is better, join us on the dark side,…
I don't see any problem with using whatever pleases you (even if those are very obscure tools), if with transition you don't lose ability to use less convenient (but common) tools on occasion. And you usually don't lose that.