What do you mean by there should not be a market for them? Markets tend to define themselves.
The question is what do you get from an SUV which you can't get from other cars?
BTW statistical they are no safety than other cars, as whilst you may well have a marginally better view of the road ahead, they tend to be heavier and so take longer to slow down.
Their boot space isn't much better (and certainly not as good as estate cars).
You can't carry more people (unlike people carriers, which they have often replaced).

