In short, these folks couldn't agree on what it was, but they could agree on what it was NOT: a role-playing game.
In reading threads about Mass Effect 2, I have seen the complaint that it is not a role-playing game crop up with surprising regularity.
Of course, no one can say ME 2 is "video gamey" as an insult, nor could they really call it a board game. Neither of these work because the game is clearly a video game. It comes on a disc in a box and you install it on a PC or play it on a console.
But when I look at Mass Effect 2's design decisions, and compare them to 4e, I see a lot of parallels, and both games are getting the same reaction from some fans.
Both games reduced resource management. In older editions of D&D, you had spell slots and abilities with very limited uses. As THE king of resource management, the D&D magic-user required a different skill set and really a different mentality than the other classes, especially at low levels, when unleashing that one Sleep spell you got for the day at just the right moment was as much art as science.
4e drastically reduced resource management and what resource management there was, all classes played the same way. Meaning a Fighter had different skills and played differently in some ways, but the resource management required to play a Fighter was the same as that required to play a mage.
Mass Effect had a lot of similarities. Adepts (the psionic characters of the universe) had to carefully choose when to unleash a devastating psychic ability, else they be caught with nothing but a lowly pistol to defend themselves with at a crucial time.
There was also omni-gel, a critical component for lock-picking, hacking and vehicle repair that you could only get by breaking down unwanted weapons and armor that were constantly cluttering your inventory.
I know there were times in Mass Effect where I agonized over breaking down a weapon early in the game because I needed the omni-gel. Late in the game my inventory was constantly full and I would sometimes spend 30 minutes breaking down items into omni-gel so I could pick up new items.
I was literally drowning in items (and omni-gel) but I kept making more because I had a finite amount of space. And boy, was it a lot of space.
In Mass Effect 2, inventory management is almost completely gone. You occasionally find a new weapon but most of the time you are improving the assault rifles for your entire squad, and this happens automatically.
Omni-gel? Gone. It still exists in the *fiction* (you hear some radio ads for omni-gel in the game) but as a vital resource players were hoarding at low levels, and swimming in at high levels? Totally gone.
Power recharge times were drastically reduced. Your Adept really can, in most cases, rely on just his powers.
And the claim? Not a RPG.
I think what we're seeing is that many players see resource management, even when it's a huge time-sink, even when it's a pain in the ass, as an essential part of RPG design.
And more and more designers are trying to eliminate these time-sinks and allow players to spend more time PLAYING, and less time staring at inventory screens (or sheets of paper).