I'm so tired of hearing people use the term vanilla to deride those things, those acts, those people they think of as boring, conventional, unimaginative, and unadventurous. Particularly, when, as is usually the case, this is a judgement made within a sexual context.
It's not merely that this shows a vulgar lack of appreciation for what is actually one of the most precious and sophisticated of spices - lacking in flavour only to those who lack subtlety of taste - but I suspect there's an underlying misogyny here too; in particular, an all-too-common hatred of female genitalia.
For not only does vanilla have a complex and seductive bouquet like the vagina (delicate, yet overpowering), but the word itself is of course the diminutive form of the latter.
Those individuals who enjoy other scents, other tastes, other points of entry to the human body are at perfect liberty to do so as far as I'm concerned - but, seriously, we can all do without kinky condescension and eurotophobia.