First, let me state that I agree the mentioned sentiment 100%. For me, I enjoy the process of raiding. Taking on the bigger and harder encounters, challenging me to excel and do better, to learn and master my craft. However, to think that loot is completely secondary is a big mistake, because no one here can claim, with a straight face, that they don't like receiving loot. So, obviously loot does matter, but where is the line of good taste?
We all know there are people in the game who are willing to ninja and steal, horde it all for themselves if we only let them. In a way, because of those, it is one of those many touchy subjects, when you usually receive minimum the bad looks from your peers when expressing frustration of not having the luck in the rolling. However, that is hardly fair because loot does play an important role in the game of warcraft.
After all, without proper loot, you have very little business even in the easiest raids and when you lack the certain level of gear, the performance you put out will become stomped. So in my mind, a much better definition for loot is that arguably, it is not the most important part of raiding, but it is indeed a essential part and without it, eventually the process will lose its meaning.