Yes. Absolutely. Even though it is true that Gary Gygax gave explicit permission to play in other ways, every game (including 1e, 4e, and RCFG) is designed to be played in a specific way. The designer's views of "the best/most fun way to play" informs the design goals of the designer(s), whether they are aware of it or not.
Gary Gygax was merely upfront about what he thought was the best/most fun way to play, and why. Some of his reasoning I agree with; some I do not. However, his reasoning and design goals are different than the reasoning and design goals of the designers of 3e, 4e, and even 2e.
Heck, the design goals of AD&D 1e and
Basic D&D are explicitly different.
Any game has its "best play" experience occur when the user and the designer have the same end goal in mind. Note that I do not mean here the best play experience a given specific person can have; I mean the optimum experience available to the optimum user for that system.
Sure you can. All you have to do is make humans, in some way, the best choice. It doesn't matter what way this is done in. All that matters is that it is done.
IOW,
if all options are equal, there is no "central" option.
It was an intentional design goal in 3e to decentralize options (as opposed to the humanocentric 1e). I would argue that decentralized options were an unstated goal of 2e, which saw splatbooks for every race except humans, and saw official endorsement for monster PCs.
1e's mechanics were informed by its design goals. 2e's mechanics were modelled off of 1e's, but the design goals were far more similar to those of 3e. It was a mismatch of mechanics and goals that, ultimately, hurt the system. 3e was not "1e with better mechanics"; it was, if anything, "2e with better mechanics (in some cases)". Prestige classes offered a more balanced take on kits. The 2e skill system was refined and improved. The 2e idea of the bard was retained. Even the early 3e spaltbooks followed the basic model of the "Complete Book" series.
And, perhaps, for the majority, the design goals of 4e, 3e, and/or 2e lead to a better game than the design goals of Gary Gygax in 1e. But they are different design goals, leading to different "best play" experiences. All this means is that these games have a different set of optimum users.
You know, I've never heard anyone who prefers checkers to chess claim that checkers
is chess
with better rules.

Perhaps we are letting the name of the game(s) blind us when attempting to view what these games seek to accomplish? 4e can "be D&D" without being "1e with better rules".