Any goths I have seen kilted have worn the more contemporary type of kilt, not traditional at all.
Having said that I should say I am not into the goth culture, however I do have tattoos, traditional kilts, and a 14 yr old daughter who has friends and may be leaning towards gothic culture herself.
I am sure that they would find the traditional kilt cool as it is outside the norm.
So in answer to your question I suppose that kilts are indeed goth wear.