people keep buying them, so they don't have a ton of incentive to tighten up quality control. That adds cost. Until there is enough competition that they have to compete on quality vs cost I don't see it changing. Its not just tubes, other parts have gone to crap when there are less options and mfg compete purely on price. Car parts have become a real gamble for fit and function. Last water pump I bought didn't even fit. I discovered this after it had been painted (aka no return) and I had put the gasket sealer on. My nicely painted water pump now has a big rusty spot on top where I took a grinder to it so it clears the thermostat housing.