We have a shell tag, but we also have more specific shell tags such as sh and bash. Many tags with shell also include these specific tags, so it almost looks redundant. I could see that there are other questions without specific tags, and I assume they would still need this tag. Should we still do something about it to help prevent it from being "sprinkled" over different questions that don't really need it specifically?
I think this tag has a value. It can help users proficient in shell-scripting (in all its forms) to find questions that are doing shell scripting.
There's some common standard errors in shellscripts that are applicable across all (or at least a large number of) shell specializations.