Hello Edena. A few observation about your conclusions...
The human drive to dream and imagine is effectively infinite.
Join a local writer's group or take a few creative writing courses at a college and see if you still believe this...
An error in the initial protocol lead to the institution of taking for granted the changing of D&D rules.
The tradition of being encouraged to customize, personalize and otherwise modify D&D's rules is, for my money, D&D's greatest strength. In a way it foreshadows the whole user-created content/mod movement found in electronic games today.
I love that D&D has always presented itself as a rather loose get of suggestions/guidelines for play. It's this that makes the game 'as big as your imagination' (which, if we're being honest, probably isn't all that big...).
That institution snowballed by a long process (that took many years) into an institution of intolerance, anger, and hatred.
This is just wrong. Well, mostly.
It's my belief that the problem your describing comes from the whole player/DM power imbalance. While the power relationships in traditionally-run RPG's are fluid by design, the majority of the power is placed in the hands of one player who is rules arbiter, rules implementer, and player-of-the-opposing forces. This is the root cause of most, if not all, conflict. Since the power relationships at the table aren't fixed (as they would be in game like chess), people jockey for power. This takes many forms; rules arguments, real-world physics arguments, playing bullying characters, but in the end they're about power.
Of course, the inherently unbalanced player/DM relationship is also RPG's greatest asset. It allows for a freeform exploratory mode of play, full of varied challenges, that no traditional board game can touch.
Any new incarnation of D&D, should come with an etiquette that stresses the importance of rules, the need to obey rules, and the serious gravity of changing rules, while at the same time offering as many templates of rules as possible since the dreams of Gamers encompasses vast expanses of the imagination.
Ed, the above combines the best elements of wrongheaded and impossibility. Etiquette is simply a respect for other people. It has nothing to do with following the rules-as-written, so long as people are informed of and consent to the changes (or the possibility of a change).
Really Edena, the problems faced the gaming table can all be solved by simple communication, negotiation, and compromise. I've run a rules-loose 3.5/AE campaign for over 4 years now, for friends who most assuredly
do not want the same things out of D&D. It's been a blast. You can read about the campaign if you like... we have a Story Hour (see sig.).
The no rules, or amount of respect for them, can solve what are fundamentally interpersonal problems. I can --in a limited way-- agree with you that the rules can contribute to these problems. But no rules-based solution for them exists; not without crippling the best part of the game.
The real world and it's demands, and the logistical problems of setting up a D&D game, will remain obstacles.
Now this is the biggest problem tabletop gaming faces. Best thing WotC could do about it is drop the DDI and partner with an outfit like Facebook.