At the minimum, it's not "fraud, plain and simple" because there are people that currently use it and are happy with it. And it's not just sunk cost fallacy because you can buy it as a subscription for $200/mo, which is much less of an investment, and you can cancel that at any time. I don't know if Tesla breaks out numbers of how many FSD subscribers there are, but I think that would be pretty interesting to know.
Regardless, for something in development like FSD, I think the subscription model makes the most sense, since you know kinda what you're getting and if it's not worth it to you, you can cancel and then try again later after some updates. I kind of think they bumped the price to $15k just to switch more people to the subscription model.