My grandparents always make fun of me when I listen to J-Rock too >.< my grandfather says "I don't know how you can listen to something you can't understand.", even when I tell him I am beginning to understand lyrics (thanks to Japanese lessons
)
I remember another time, my brother (who's nearly 2) came over to our house when I was listening to Dir en grey and he actually quite liked it (from what you can tell from a 2 year olds reaction XD) but then my mum came in and said "Turn that rubbish off!".
I think if people gave Japanese music a chance at least they might like it...my friend did and now she loves it XD