I generally agree with that, with the caveat that the top 10% of anything is closer to indistinguishable. For example, there's a very clear difference between Paris, France and Paris, Texas. However, once we've narrowed the category down to "popular vacation destinations" or something like that I think the differences are narrowed.
As someone who enjoys bad movies more than good movies, this is simply not true. Pick any 6 random games on Steam and see if you find 2+ of them moderately enjoyable.
There really is just a lot of crap out there, and not everything is meant for everybody. Also over time gaming has become more mainstream which means more people interested solely in money, a larger audience for more niche genres, as well as half-assed hobby projects since Steam Greenlight (which is now Steam Direct) have cropped up over time.
I get the gist of your argument and there's something to be said for just trying something new and enjoying it. But your argument is roughly equivalent to "buy a plane ticket anywhere in the world and enjoy your 1 week vacation!" Chances are most people would prefer Paris, France to Paris, Texas. Even if a few people would actually enjoy the different experience equally or more, most certainly wouldn't.