"okay, what descriptor can I use that isn't going to cause another thread?"
A generic question that is asked quite often-- and seems to cause no end of problems.
Quite simply, just use a term that is both polite and respectful. If one is unable or (and I find this much more likely) unwilling to make that very simple and very easy extra step, then maybe it's time to ask someone who's a member of that group to give you a non-offending term.
It's simply not very difficult... although it does require that we choose not to offend people (which is most likely the problem-- as many of us merely wish to insult others in such as way as to feign innocence)
Fights over words are very, very simple to avoid-- simply choose our words somewhat carefully, and holster the desire to cleverly insult through back-handed compliments, another poster through the use of those words. Neither premise nor conclusion is strengthened or validated through insults; hence, we may suppose they are wholly optional to any conversation, yes?
If we are using a phrase, or a label, or a name that offends someone, does it deny us anything of any real substance to find another word, or another phrase, or another label in better standing? Is our vocabulary so limited as to be denied our point by not using a particular word? Or are we merely attempting to hurt another person in a manner that we can justify (to ourselves if not to anyone else)?
If we're looking for a fight, we know the words to use, the buttons to push, and the limits of how far we can take it ("clever enough to be dangerous, but not clever enough to assist anyone" as dear old grandad used to say.) I say this as someone who has been doing that very thing more and more often lately-- letting my visceral reactions take precedence over an exchange of thoughts and ideas. However, I am wrong in doing that-- I certainly cannot rationalize it, and it does little more than advertise my character for many, many other posters to see.
So rather than continuing to ask a new variation on the same question "what is an acceptable way to insult another poster?", I will simply try not insulting other posters instead. It's not the Word Police, it's not a Net Nanny, and it's not big-C Censorship... it's simply not insulting anyone.
Or not... but then we're simply justifying to ourselves that some insults are acceptable, and others are not-- which is an absurd argument to have with ourselves either way.