They couldn't just jump on every technically superior idea, because compatibility is a thing too. And, by the time everyone agreed that utf-8 was preferable, compatibility with their own stuff, which is always especially painful.

It's not as if they were the only ones. I had a lot of utf-related pain in the Linux terminal back in the day.

Vi and Emacs took a long time to handle variable length encodings well. My old Unix editor of choice, NEdit, never managed the switch at all.

I got a mail from my boss in utf-7 once. God knows how that happened.