Dictating to other people how their personal workflows should look: Hell No
But if he was, it would be OK, no?
Ligatures and substitutions are display only.
I can setup my ide to display how I want it to display code. It affects no one else.
Why should any manager dictate that to me? I'd not be working for someone like that. Feels that it would be someone on a huger power trip.
Imagine dictating what font your Devs have to use... That would be mental.
It's called "discourse". Differing opinions are voiced and compared to each other, not in search of "Universal Truth", but because different things work better or worse for different people. Greater awareness of the scope of possibility allows individuals to find the things that work best for them. Society as a whole benefits, eventually; at the cost of lots of noise... which we seem to have regardless.
Either you like them or you don't and it doesn't affect anyone else's machine. It doesn't matter if it's pure Unicode or whatever loosely connected complex faux objective reasoning you can drum up to support your subjective view.
I didn't like them, but then I did get used to them and I prefer them for JS/TS (only FiraCode's specifically), let me stretch that into an article...