Mostly, this applies to ice. Now, many of you in the north are currently driving something equipped with studded tires or really good all-weather treads, and if it's a pickup (and quite a few sedans) there's a bag or three of kitty litter / pea gravel over the rear axle. This enables you to drive normally on truly cold ice and scraped snow. It doesn't help as much as you'd think when it gets right around freezing/melting point.
In the south, "snow" and "ice" never gets very cold - it's always right around that 28-34 F range that even Alaskans dread. Southern ice usually comes with "running water on", but since it's such a rare event, they don't distinguish in the many categories northerners hold. This, along with unfamiliarity, is why they're such terrible drivers on ice and snow: even in Anchorage, I did not look forward to driving on running water on ice, and stayed home if I could.
No matter where you live, if you're going to fall on your butt (hopefully) or shoulder with a wrenching and tearing feeling (hopefully not) when trying to get to the car or through the parking lot, it doesn't matter how well you drive... you still shouldn't be out.
This is like "Nothing good happens after midnight." It's a good rule of thumb that keeps people out of trouble.
If you can't walk on it, don't drive on it.