Well, I wouldn't agree with laughing about it, but it's not the clear cut. You've done well with your mower quite clearly. However, some of the newer ones have such terribly fuel delivery systems, simply out of cheap parts, that the engine isn't worth maintaining, particularly given the throwaway pricing on some of these products.
They'll sell the new mower for under $200, with an eighty cent fuel system, but you have a carb problem, the carb is like $150 or something ridiculous like that, and I've even seen the carb and engine cheaper than the carb itself. Of course, it's worse up here, with the lack of competition.
So, it's fair to be skeptical. I could change the oil in an OCD fashion twice a season on my mower with whatever is specified or something far exceeding the specifications. Or, I could just keep it topped up with whatever I find laying around. It's not likely to have a lube related failure in either case. It's going to be something else that will cause the thing to be thrown out.
Both my snowblower and my mowers have had fueling problems, despite not having seen any E10, either. That's just another excuse by OPE manufacturers. Instead of making a fuel system that can last more than two seasons without a complete R&R, just blame the fuel.