To be honest having been in the music scene for many years, any type of music can and will at some point become popular.
I listen to a lot of hardcore and have played in many HC and punk bands. when i first started out we all thought we'd never see the day when radio 1 would play anything we liked let alone have an entire show dedicated to it!
At the end of the day, it doesn't matter. Scenesters will come and go, it's down to YOU to love what you love no matter what the "mainstream" are doing and stick with it. That way the music you like will never die out.
I personally can't wait for the bertie basset lookalike floppy haired wank stains to leave my type of music alone and go back to listening to techno. They're wrecking local music scenes round the country by not supporting the local bands properly.... but that's a whole other rant