They're all rich and friendly, they're basically "nice" people, and you're not rich in their league. They're "trying" to help you fit in, but somehow everything they say just helps to heighten the feeling that you aren't equal and don't belong. You roll with the punches, you aren't offended, but you are alienated. You'll make the best of the night, but next time you'll try harder to avoid going.
Which is fine for an informal night with strangers, but it's not the feeling a trying-to-be-inclusive professional event wants to invoke in significant fractions of the population. It's the difference between them "trying" to be friendly (in quotes - meaning acting how they would act to each other to be friendly) and actually being friendly in the all you have to do is whatever it takes sense.