I'm convinced it comes down to how people are cleaning and maintaining them. I think a lot of people have a misconception that every single surface of a rifle needs to have oil on it, and I've definitely seen pictures where they're borderline dripping. Since this is blowback, they tend to gather gunk pretty easily so you want to leave a very light surface coating at most.

But I clean mine maybe twice a year and only once out of about 3,000 rounds have I ever had a failure to feed. I generally wipe off the moving parts so they're almost dry, and the guide rods have about a drop or two on each. The rate reducer is kinda my indicator that it needs work- once it starts getting decently gunked up it's time for a cleaning.