I think we can do without it. The utilities tag has almost full overlap with shell. The few cases that do not overlap would specifically be better tagged with some other combination of tags.
It's true that it's sometimes used in a meta-ish way: on some questions, it doesn't seem to provide any information. On a couple, it means “I want to do this on the command line”, and we use command-line for that. But this means that these questions should be retagged, and I've just done just that. Since I feel the tag does convey useful information, I'll leave it on the other questions.
There's now a tag wiki, as well.