Using a blanket statement saying that stock tires suck is misleading. There are several very different types and brands of tires our trucks can be equipped with from the factory. Some really are bad in wet or winter conditions, but some are quite good. Before we can blame the tires we'd have to know which ones he had. It's obvious that he probably didn't have the Falken Wildpeaks that come with the ORG, since they do very well in the snow. But if someone is inexperienced at driving in low traction conditions, they can have the best snow tires known to man and still have problems driving in snow. Another variable is the type of snow. Wet snow and slush is one of the worst conditions you can drive in, while dry powdery snow is much easier to get around in.
The best tires for all winter conditions are dedicated snow tires. I won't get into which brand I think is the best. Suffice it to say that for driving in winter conditions, the worst snow tires are better than the best all-season tires. So if you really want to be safe buy some snow tires, and swap them out seasonally with whatever tire you want to use the rest of the year.