As it happens, this strategy has already popped up with more concise wording

Alas, I am not every provider, so I can't give feedback on how well it works for securing a booking generally, or as a method for getting around stated boundaries.
I want to clarify that I don't have the kind of policies that we're currently discussing, and I don't filter my clientele by such broad categories. But I'm also not going to pretend like I don't know why these kinds of policies are a phenomenon, and I'm noting that there may be a bit of a gap in our understanding of that.
Like you I agree that people can change, and there are people who are unintentionally disrespectful or less pleasant to see purely because they don't know the etiquette. These people are usually pretty obvious in person, and I'm more than happy to give people pointers - I was the teen who suffered for unspoken social rules so I get that pain. Unfortunately, when you have had someone literally laugh in your face for having boundaries, it becomes clear that the issue has nothing to do with knowledge of etiquette. The reality is that there is a subset of the client base that doesn't believe we are real people - who find the idea that they don't get to do whatever they like with the merchandise they have purchased so absurd it's actually funny. And then there are the people who find that succeeding in the "struggle against friction" is most of their fun, and who approach things like premises bans as mere inconveniences rather than a sign they've done something really wrong.
This attitude is not limited to Indian men, and the majority of Indian men do not think like this. But the majority of people who think like this do come from certain subcultures within "Indian culture," (which I put in quotes because the country itself is so vast and varied that there isn't a whole lot that is common across all 1.4 billion people) When the level of disrespect is what it is, you can understand why some providers prefer blunt tools over the stress of having to assess on a case by case basis and then risk getting it wrong.
Personally, I prefer a more fine-tooth comb as I find it serves me better across all demographics - and if I took a broad-brush approach I would have missed out on some really sweet regulars. I have also met Indian immigrants whose awareness of the stereotypes shows up in an obsessive approach to hygiene and an insistence on letting me lead so intense it becomes complete passivity. So yes, this is an issue. But I also understand why some providers take the approach that they do.
Can I suggest that if this kind of advertising applies to you, that provider is saying something about her own ability to provide you with good service? That doesn't make things hurt less I know, but at least you know that before you meet in person and hand over your hard-earned cash. And even if it doesn't affect you, please understand that the most anyone can really do is to keep speaking up and (calmly) pushing back when you hear problematic attitudes.
(That call for calm applies to a few people in this thread by the way......)