Ashreinu,
If frum means trying one’s best to serve Hashem, then it is only a good thing.
However, frum can be used with a negative connotation meaning frum but not ehralch; focused on chitzonius instead of pninimus; careful in bein adom l’Makom, but not bein adom l’chaveiro; overly concerned with judging others frumkeit; etc.
We all know people like that. (Not that there is ever anyone like that on YWN!)
Personally, I prefer being called Torah observant.