It's the marketing of them that rubs me the wrong way. If they were 'mini ovens' or 'countertop ovens' or whatever, fine, and I have no problem with anybody having, wanting, or liking one while understanding that is all it is.

It's largely from disappointment - I assumed initially that they were designed to save oil vs. a deep fryer, that they blasted jets or misted oil over the food. That I think would be novel and interesting.

As it is, if you have an oven already, the RoI is too long to do it on a cost basis. Maybe there's an argument of time-saving as they pre-heat a smaller box quicker? Hardly takes long as it is, I think that's a stretch.

If you don't already have an oven, then yes, if the capacity is not a problem then it's a great option, they start cheaper than bigger ovens... Obviously I suppose.

(I suppose I shouldn't have generalised so much above - I was speaking from my experience in the UK. Other than perhaps a tiny studio flat (single room apartment, no separate bedroom) I would think it's pretty much unheard of to rent somewhere without one here; buying it would normally (almost always) be included, but if not there'd be an obvious gap where yours or your newly purchased one would go.)