-- Last Updated: Feb-07-13 1:55 AM EST --
I guess I don't fully agree that it isn't a boat problem, but a skill problem. Rec boats are meant for flat, protected water, and whether skilled or not, if they flip away from shore, they are near impossible to get the paddler back in and boat dry. Added skills just minimize the chance of the paddler getting in trouble (hopefully the skilled paddler knows what to avoid more than the unskilled).
The way I see it, rec boat designers are trying to take the best of touring and SOT and bring them together. SOT are wide, stable, etc., but you sit on top so are exposed to the elements and generally always wet. Touring you sit inside, so are protected from the element, but in a narrow boat that many think are tippy.
Rec boats are wide and stable, but you sit inside so get some protection from the elements. Unfortunately, the trade off is that should you find a way to flip the rec boat, it is nearly impossible to get back in while on the water. A wide boat should be less likely to flip, but it can happen. And using them in larger conditions (like waves) increases the chance of flipping.
Actually, on that - a wide boat will want to sit flat on the water. When the water is flat, the wide boat feels very stable (very high initial stability). But if the water becomes wavy, that wide boat tries to stay parallel to the surface, but these waves make more vertical surfaces. So the wide boat gets vertical. Narrow boats, like touring kayaks, don't have that super high initial stability, so are better able to let waves roll under them without the boat getting vertical.
On deck lines and all, truthfully that isn't a rec specific thing. I still remember touring kayaks that didn't have deck lines (though it seems that most now come standard).