Usually the problem in the OP pictures are from pellets that got damp somehow. They then disintegrate very easily. I've been running pellet grills for about 10 years now and (knock hard on wood) have never had this happen yet. I don't clean my pellets and have never vacuumed out an auger. I'm careful with pellet storage though and don't do silly things like pour all of the dust from the bottom of the bag into the hopper, but I do see some dust fall in when the pellets pour sometimes.
There are mechanical pieces to pellet grills, eventually there will be an issue or two, but it's not a regular occurrence for most people with a little common sense. Pellet grills have a lot of smart users, but they also attract a lot of people with no grilling experience whatsoever because of their advertised simplicity.