A way to move to fish gradually is to use it on your local machine (interactively) but still write scripts in bash and stick to bash on remote hosts. This helps keep you in sync with others.
One drawback is keeping your aliases in sync, but once done it is not much work.
This is what would be keeping be back I think. I spent too much of my day in remote shells on systems where I do not have root. This shell looks really cool, but I am afraid that I would come to depend on its features and thus lose my bashfu skills in the process.
One drawback is keeping your aliases in sync, but once done it is not much work.