Anyone know why the old csh is now codice non grata ? And what's so freakin' hot about zsh ?

[Tasmanian Devil]

2. csh is old

Csh is from BSD (older than Linux) and is buggier than bash, especially when writing scripts. For more info check out the end of the wiki page on it: csh reception

But I think the bottom line was just that fewer and fewer people are sitting at shell prompts and scripting (and sh) won the shell wars.

That said, I always set my interactive shell to csh and run background stuff with:

nohup program_name < /dev/null >& output.log &

I.e. just add nohup and deal with stdin, stdout, stderr. Not that much to teach your fingers.

If csh/tcsh is not included in Manjaro, I'm pretty sure you could download the source and build it: see https://github.com/tcsh-org/tcsh