Sure there is. 99% of everything else I've ever experienced in my life have had a positive correlation between features and price. I'm actually struggling right now to think of another product where—in general—more features are cheaper than fewer. Other than television sets, I cannot think of one right now. (Maybe if I spend some time on it, I can think of another) Therefore, knowing what I know about prices of things, it is totally reasonable to assume that TVs follow the pattern.
If you truly don't understand this distinction, then this whole conversation (indeed, this entire posting/thread) is hopelessly beyond your comprehension.
Thanks for confirming my suspicion; the fact that "it's a feature not a bug" is pretty unethical has nothing to do with whether it can successful or not. It's a useful logical tool to learn to distinguish "is" from "ought"; whether or not you think that Smart TVs are better than dumb TVs or not has no bearing on whether or not they're marketed as such and most importantly believed as such by the majority of consumers.
Hell it's not even one of the worst heuristics in play: (higher) price and popularity of a product as a heuristic for quality may be even worse than "more features" as a heuristic, and these two are extremely prevalent. And yet just because I don't like them doesn't mean I pretend that these tendencies simply don't exist.
An assumption is reasonable if it follows logically from facts we know about the world to some conclusion. For example, cars with more features usually cost more than cars with fewer. A washing machine with a detergent dispenser and 11 different wash modes costs more than one with 3 modes and no dispenser. A thermostat that just sets the temperature and does nothing else will almost always be cheaper than one with wifi connectivity and a companion iOS app.
Based on that knowledge, its reasonable to assume that a TV with more features will cost more than one with fewer. This assumption is wrong of course, but it wasn't unreasonable.
So that means an assumption is unreasonable if there's no reason you'd make it in the first place.