You haven't made any argument.
And lots of industries ban unprofitable customers. All-you-can-eat restaurants will ban customers who eat/take absurd amounts of food, which is unprofitable. Landlords don't rent to prospective tenants who have a history of not paying rent, which is unprofitable. Every major retailer will ban you if you return too many items too often, which is unprofitable.
So why would betting be any different? Banning highly unprofitable customers is normal business practice across many industries.
There's a reason we call it the free market rather than the forced market. Businesses aren't forced to transact with individuals (unless they are discriminating against specific protected classes like race or gender).