All PvE content in all other games is easy two years later. This is obvious.
You claim to be a hard core WoW raider and you've never heard of Death and Taxes? Maybe so, but your analysis is pretty bad at the same time. A dungeon that can be solo'ed once you have the appropriate skill and experience is the mark of good design, not bad design, but that's purely opinion.
About rampagers being ill conceived, I strongly believe that Arenanet did not realize what a well organized party would be capable of. As for 2+ minute fights, which 5 man boss fights do you have in mind? I'm not asking that sarcastically, I just can't think of an enemy that takes that long to kill, unless you're soloing or unless it's Mai Trin.
Mossman at 50+ is at least 2 minutes, Archdiviner is about that length too. None of the named dungeons really have any fights of that duration since most people figured out how to melee lupicus and use Fiery Greatsword.