I'll just use the same argument people use when recommending performance summer tyres over ditch finders. They'll be fine until you really need them. In this case they're fine until you hit that patch of ice and don't stop, whereas the all seasons or winters may well stop you before you hit the ditch/lampost...
He's looking for tyres for a crossover, not a high performance saloon. A decent set of all seasons will fit the bill if he doesn't want two sets of dedicated tyres. Besides, they'll make his crossover look a bit more SUV like.