I've been on both sides of the equation, having disagreed with sysadmins about their enforcing of a particular login shell, and having been a sysadmin myself. Not installing fish shell on production systems ("across the farm") is something I'd chalk up to wisdom, not a lack of open-mindedness. I was subtly suggesting that in my choice of positive adjectives.

Really, you shouldn't be logging in interactively into production machines, so no need to install extra tools by default.