Having empirical evidence and hard data, or learning from the testing of others is having your hand held? Many people can "see" they do less damage than another spec if it's a significant enough difference, but they either aren't sure why or aren't sure how they can improve. For example, Sorcs in pure 31pt Lightning or pure Madness do less damage than hybrid specs. I've come across plenty of players who can see their pure builds aren't dealing as much damage, but they aren't sure why until they come and read what others have discovered. Others just "eyeball it" and while that works for gross displacements in numbers (both healing and DPS), it doesn't work in the 10-15% difference range during an all-out skirmish. Obviously most references here are in relation to WoW, but FFXI had a brutally complicated damage, accuracy, and combat action speed system that was not properly discovered until various members of the community took large amounts of time and raw data gathered from parsers and combat logs to figure out. Once that information was verified and widely available, it allowed players wanting to do their perspective job better to look at gear, stats, and actions in a more efficient manner. Yes, there will always people taking advantage of other people's gathered data and not understanding the mechanics of why it works the way it does. Yes, some will be immature enough to say "I'm the best, everyone should have this spec, etc". That is not a reason to staunch the community at large, much less condemn it. Regarding the situation of "Well this spec does more than just DPS, it also does CC and backup heals". That's certainly a viable statement, but then it's up to the group leader if they want to dedicate a body to doing that. If the healers or tanks or DPS could be made more efficient to the point of outmodding that spot then perhaps the group would benefit more from replacing the "backup" guy that is there to pick up slack with someone more dedicated to a particular role and there not being any slack to pick up.