The best thing about them is that they are easy to get into and out of (particularly if your knees aren't good), and spacious if you are tall and have long legs (I've had a Vectra estate which is a good large car, but any car where you sit near the floor isn't good if you have long legs and shortish arms - very rarely does the wheel adjust enough for it to be as comfortable as a more van-like driving position).
If you don't want to drive one by all means don't, but lots of us like them. Most of the advantages can also be had from an MPV, but Euro SUVs are the same sort of thing but look better*, so why not? Most aren't even 4 wheel drive so you don't have the transmission losses.
* To be fair the Kuga and C-Max look very similar, but that just adds weight to my view that Ford basically only make one car, it's just available in different lengths and heights