If you put snow tires on it, which you absolutely should do regardless of the drive system in snowy areas, it will be fine.
If not, well, it really doesn't matter if the system can help you get moving when it does nothing to help you stop.
I think a lot of people are too hard on these sorts of vehicles anyway. Sure, they're not X-TREME ROCK CRAWLERS, but honestly how many people actually do that anyway? Even the vehicles capable of handling the Rubicon are too expensive to risk damaging them on a trail. For on road driving in bad weather, they're fine, the added clearance helps for deep snow and the AWD systems are generally good enough.