I don't see why you're so surprised, OP. In the beginning there was only bitcoin. But now we have over 300 different cryptocurrencies. Bitcoin is great, but it's obvious that the amount of posts created about bitcoin simply can't outnumber the plethora of posts for each and every one of the new and old alts out there.

It's just numbers.

That said, if people want more BTC threads and posts, just post more. And yeah, if the altcoin posts are annoying you -- it's time to ignore those boards.