I think you are confusing 'performance' with 'consent'. Sure we meet a lot of people we don't know and it's an unusual circumstance, but the minute we agree to the booking, we are mentally preparing ourselves for what we are going to do and getting ourselves in the right frame of mind. For me the kiss is very important, as that gets my body reacting, but right from the start I know I'm going to spend time with someone who finds me attractive and wants to spend time with me, so why shouldn't we have fun together? The money is what brought us together, it is what is going to pay my bills, but that doesn't mean we can't make a connection, enjoy each others company or have a good time.
Ultimately we have control and if we work within our boundaries, we should be able to enjoy the experience too. Even if at the end it is to think, 'What a nice bloke'.