It's not the kinky sex ... I'm a voyeur and I've had partners who are exhibitionists. It's not even the casual nature of the request ... I endorse casual sex providing everyone involved is getting what they want out of the relationship.
It's the fact that I very clearly state, in the first goddamn paragraph, not to email me asking for casual sex, kinky sex, or anything sexual at all. This email reads like a form letter. These two details tell me that this person doesn't give a shit about who I am or what I want. He didn't take the time to read my profile, or if he does, he blatantly ignored an explicit request, and he didn't take the time to even construct a unique first-contact email.
People just don't seem to understand that lack of anger does not = "polite". The fact that he didn't call me names or assault me or do anything aggressive or violent is not the only thing that makes behaviour "polite". When someone makes a request of you for how the person wishes to be treated, and you ignore the request, do the opposite of the request, YOU ARE NOT BEING POLITE EVEN IF YOU USE NICE WORDS.
The Golden Rule is bullshit. Don't treat people how you wish to be treated because everyone wants to be treated differently. Treat people how THEY want to be treated. Holding open a door for me is not polite when you have to tear it out of my hands or argue with me to get me to relinquish the door. You could make a case that I'm being obstinate, but that doesn't change the fact that YOU not being polite if you do something I ask you not to do, no matter how good your intentions are or how pretty the words you use are.
So, public ridicule it is!