I realize this thread was inspired from another in the MM forum, and it was there I asked the same question - why does the term "plate" bother you?
My guess is that it seems offensive to guys with feminized sensibilities. I say that because calling a woman a 'plate' comes off as objectifying women in a certain context. Now obviously women will take offense to being objectified, but it's men who seek to better identify themselves with the feminine that who'll be similarly offended. This then comes back to men - and those struggling against an AFC mindset in particular - wanting to separate themselves from "other guys" by better identifying with the women they hope will appreciate their doing so.
All of this is kind of a moot point though, because my intent, even as far back as 2005 when I wrote
Plate Theory, was never to objectify women by referring to them as "plates". Rather, it was a term of convenience that the members of SS popularized. A "plate", by my definition, refers to any woman you are interested in that you maintain a non-exclusive arrangement of intimacy with.
The operative in this being
non-exclusivity, and this, I believe, is what you're finding hard to chew on. The properly feminized male usually internalizes feminized social conventions for himself (i.e. the more alike he is with women, the more they will appreciate him). Thus feminine imperatives become his imperatives. Yes, women are all unique works of art that should unequivocally be held in respect like precious gems - how dare you call them 'plates'?!
I could just as easily have referred to women you're non-exclusive with as "da b!tchez yo working" or something more or less offensive, but its not the term that irritates you, it's the principle of non-exclusivity that does.