Sure they can win here. Their advertisement for Gold literally says "access to margin" on one of its selling points. How is anyone without Gold supposed to read that without mistakenly concluding they don't have margin? That's misleading if not outright deceptive. They can easily "win" by... removing that clause, and (optionally, or not) replacing it with something like "access to margin beyond your portfolio value" or something. It's not that they're already doing things as well as they can and the problem is just too complicated to simplify further. They actively mislead people.
And note that "borrowing money" does not imply "have margin" for people either. They might realize they're borrowing money, but not realize that has further implications they might not expect, like the broker being able to sell your stock without your approval. If they actually use the word "margin", people could at least look up what it means and likely realize it's a nontrivial topic. But just saying we'll make $X available to you makes it so much harder for them to understand there are non-obvious implications.
And note that "borrowing money" does not imply "have margin" for people either. They might realize they're borrowing money, but not realize that has further implications they might not expect, like the broker being able to sell your stock without your approval. If they actually use the word "margin", people could at least look up what it means and likely realize it's a nontrivial topic. But just saying we'll make $X available to you makes it so much harder for them to understand there are non-obvious implications.