The issue is you don't see this level of argument and flame going on at other communities. Take Warframe and GW2 for example, the former is predominantly PvE with PvP available to the crowd, no one is trying to kill each other on the forum over the design of the game, and Warframe is still considered in Open Beta, and it has come a long way, even when the mechanics and features were mere skeleton, the community never bickered over PvP/PvE influence of the game.
GW2 provides full-fleshed features for both PvP and PvE. Both of these games have exclusive reward for PvP and PvE, the community never tried to kill each other over the basic design of the game.
So I really don't know what is wrong with ED other than its advertisement and attraction of overly large of a crowd than the game was intended for. The reason for it most likely fall into two possibilities:
1. Corporate greed/Lack of development funding
2. Ambitious/noble vision not translating into reality
My two cents on your observation:
GW2. I play that, and have played it since GW1 in 1995.
The PvP community has always been completely segregated from the PvE community. There is a pure Co-op existence available...no PvP available, 'massive quantities of people' (well roughly 150/instance anyway) to play with..and no chance that someone is going to interrupt your day and change your mood. Even the harvest nodes are shareable amongst everyone.
For the 'hardcore PvP crowd' they have their own game. Completely segregated with it's own meta...even the skills are variants on the PvE ones (or vice versa).
For those that want to PvP in larger scale, the devs provide the WvW battlegrounds...which the devs themselves consider a part of the PvE environment...thus the skills are the same as PvE.
The WvW, just like our modes, also affects the systems of the PvE world, with buffs to various systems. This is not identical however, as there is no movement of the perception of ownership involved within the PvE part of the game itself. (edit: Nor does it offer a negative affect to the PvE world).
Where E: D differs significantly, and leads to most discussions of 'repair this or the game is going to die' posts, is two basic places.
First the only dev created place where large scale player interaction can occur is not a segregated area. This, historically, has always been a contentious issue. By not providing a PvE Open mode (one where no player can attack another), the devs have clearly stated that if players want to interact, they have to accept that they will become other players content. Yes, we all know Mobius exists. This is at best a work around to this situation. It is not a good solution...however, it probably is going to be the only one we will ever have....on any platform.
Second, people do not like the fact that the modes and the associated game play from each work in lockstep with each other. As far as I can remember, there has never been a game that tried to completely connect a game in this manner...mainly because the only way to do this, is for the game to be tied together in a constant PvE battle..with very few inputs from the PvP side of the game at all.
This creates huge dissatisfaction with the PvP crowd, because it diminishes their actions to side show status. This gets massively more problematic when players do not understand this basic design feature of the game...as PvP players, in general, have historically been given stronger agency/influence with in games by devs. When this agency is ignored, because it does not exist..the phenomena of the Open vs. thread occurs...constant demands for the historic levels of agency and input.
Finally, all players of MMO's know there is an evolutionary process with these games. No game is the same as what it was when it started.
Thus, the constant threads about improvements, loves and hates, etc. Many of the threads in these forums, unfortunately make requests that break the one or both of the above two issues....combat is only valid through PvE battles of trophy collection and that all modes have identical and completely equal input into the game.
Unfortunately, these are not issues that can be changed or evolved. They are design choices as basic as this being a space game. I haven't seen to many people demanding this game suddenly add wizards and dragons, yet. Both of these issues are tied together and are inseparable.