Vanilla represents the lowest common denominator, the ultimate pick-up-and-fap hentai story. I don't quite think Japan follows the "vanilla" concept but that's what westerners decided when spreading said tag.
If the fetish involved is big enough to be sold separately in a book, then you know it's also big enough to bother quite a big number of people, that defeats the entire purpose.
This part left me a bit perplexed
we bring you our own brand of vanilla... one that's a little broader than other people's definition of it... Will we just use it wantonly? No. Will we put it on if we think it deserves it? Yes. That's just how we roll and I hope you can all respect that...
There is no brand or broader definition of vanilla: it is or it is not. People need to stop confusing romance with vanilla, because vanilla does not require romance, it just happens to have plenty of it. The Daily Life of Souma Souko despite the 'easy lover' is vanilla.