Right, I forgot that some people talking about the 5e rules would prefer to be playing 3.5, 2e, Pathfinder, GURPS, or something else.
But... since 5e is the most popularly sold version of DnD in decades, I think it is fair to say that I am not alone in liking the game. And especially not alone in not wanting to see that major of a change made to the fundamental structures presented.
Edit:
Okay, so I wrote that before reading your second post. So, I'm going to try and save myself a headache.
I do not think 5e is perfect. I do not think every decision ever made by the designers of 5e is perfect. I do not think that we should never make the system more complicated than it is now.
However, I recognize that there are different level of engagement and fun. You might be familiar with the concept of "Weight" for Boardgames from Boardgame geek. The higher the weight, the more complicated and longer the game takes to play. One of my favorite games is Spirit Island, which is officially weighed at 3.99/5.
There are quite a few games rated higher than that. Twilight Imperium (Third Edition) is one that I know of, that I have never played, and it is rated 4.25. First Martians: Adventures on the Red Planet is 4.19.
But looking at the Overall ratings there are some differences, big ones. Spirit Island is currently ranked 13th overall. Third Edition of Twilight Imperium is 75th, First Martian? 1,881st
Now, I would be lying if I said that complexity alone is determining these rankings. Twilight Imperium 4th edition is weighted at 4.21 and is 5th overall. Likely the introduction of a new, more popular version of the game, pushed down the rankings of the older version.
But, what we can say is that complexity alone does not make a game better. Complexity needs to have a purpose, a reason for making it more complex.
Some complexity I would like to add to DnD 5e is to improve the crafting system. It has come up multiple times as something my players would like to see more of and see improved, and my own attempts to make one have been iffy at best. Better? Yes, but not as good as I want.
But the type of complexity were some types of sources of abilities, or even just the same source being implemented in different ways, work completely differently to the point where abilities meant to counter those abilities do not work? That is needlessly complex. It maybe be more "realistic" but that does not mean it will make the game better.
And backing your claim that people should just play better, think more, be better players, and then they would enjoy this complexity, is arrogant. Pure and simple. More complex games are not necessarily better, liking and playing more complex games does not make you a better player, or even more strategic. There are plenty of games that are incredibly simple, very few rules, very quick to teach, and they require incredibly skilled play and deep strategic thought. It all depends on interactions. Not Complexity.