>I don't understand why they wouldn't do it, though. I see no plausible explanation.
Money seems like a good reason. If a tiny fraction of your sales and a large fraction of your bugs are from a particular subset of those users, you don't want those users. They are too expensive.
Money seems like a good reason. If a tiny fraction of your sales and a large fraction of your bugs are from a particular subset of those users, you don't want those users. They are too expensive.