Here's what I find happens. I'll work on a script in bash because it really seems best for the job up front and quicker than coding in Python (say). The script starts to work its way up in size, 50 lines, 100 lines, 1000 lines. Then inevitably there's just "one more thing" that bash really isn't suitable for, and I wish I'd started with Python in the first place, because now I have to rewrite a 1000 line script.