While it sucks we can't get them blacklisted, I'm pretty sure we've already ruled out the "nuke the tags" and "use a dummy tag" options, and we're trying to deal with "disambiguate the tags":
Iteration the first:
Iteration the second:
- Aaronaught's answer on http://meta.programmers.stackexchange.com/questions/1946/tag-merge-discussion-jobs-career/1952#1952
- http://meta.programmers.stackexchange.com/questions/1963/posse-request-jobs-career-etc-tag-cleanup
While those questions started with thinking we could merge everything into career and sort out the rest, in both iterations, the idea of merging them into one giant supercrap tag was considered to be worse than leaving the tags as they are while we sort through and disamiguate them.
Nuking the tag seems to be the worst of these options: while we'd have lower number of questions with onerous tags on them, we'd have several hundred questions with no career-related tag floating out there, without any way to track them. It "solves" the problem of the tag being available to users < 1,500 rep, but it doesn't actually deal with the questions or tag them correctly.
And like Rebecca mentioned in her comment, [please-remove-this-tag] doesn't seem to be a great user experience either, and I don't see how synonymizing tags to it would be any less disruptive to users.
We have a problem with 1,300 questions whether they're called career, jobs, please-remove-this-tag, untagged: it's still going to take many manhours and months to fix.
If these are only three options, "disambiguate the tags", which we've been doing since July, still seems to be the best way to approach this.