Why would I want to ride on any flat tire?

A rim or any product proving itself capable of a task it was never designed for does not necessarily make it better for doing what it was designed for.

And if you really want to prove a point, then YOU get some chinese rims and ride them with a flat. Same set up, same roads, same rider.

Your revelation may be entirely due to tighter fitting tires and rims because one or more was designed to be tubeless compatible (even if not advertised as such). This in turn kept the tire in place and protected the rim allowing you to ride home on it. A happy feature for anyone who rides too far from home unprepared. But not necessary for anyone who rides prepared because they don't want to ride home on any flat. I plead guilty to that.