I think a lot of people have come to rely on what companies or journalists define as usable for the riding they do. In my opinion, if you are comfortable with the set up, geometry, and so on, and ride smoothly, any equipment will do what you want to do. Years ago, before there were 40-50 lb downhill/freeride specific rides, with overbuilt everything, people were doing the same riding on what was available, lighter bikes meant for XC. Yes, tougher parts will hold up longer and better to the abuse, but there can be a point of overbuilt, where the supposed advntage is gone, it just looks tougher. I only own one bike right now, a 2000 rockhopper pro. I have ridden everything from road commuting, urban, light freeride, and even one location that mgiht as well be DH/FR, as it's nothing but big rocks, drops, and ugly falls. Only thing I broke was a helmet and some cuts and bruises. Now in all fairness, I came from a BMX background (not as much racing, more running around DC suburbs living for jumps, bumps, and adrenalin), so I learned a lot of flow growing up.
My point is, if you like the steeper angles, the lighter weight, and less travel, then go for it, have fun, and check your ride often for damage and wear. If *YOU* think your ride isn't up to what you are doing, then you have exceeded your comfort level on what you are on, and yes, you need to get something else. Only thing your going to get for sure going to a heavier use specific bike is a set of parts designed to someone else's idea of what shoudl be used for what you are doing. And yeah probably some parts less likely to break, but you can always upgrade to them as they do break.