Teen Gothic

An example I suppose would be The Birthday Massacre. I've seen some people consider them darkwave and others synthpop, some call it gothic rock and others industrial.

I've just kinda been left in this confusion of how these conclusions of subgenre are made. I understand what makes Rosetta Stone gothic rock or Joy Division post-punk, but not something like TBM where I can't get a decisive answer.

Like I said, I'm new to this. Very new, and I'm just trying to figure out the sub genres I like by bands I've listened to. I tagged this as a recommendation request cuz I'd like some recommendations on the subgenres so I can see more of what they're all like to get a better understanding.

EDIT: Just want to say I appreciate all the feedback, I think I'm starting to get a better understanding of the genre!