100% are people that are going for the maximum. If using less healers and more DD`s for a faster killspeed is cheesing - then yes, i´m guilty of that. Isnt that what everyone is trying to do once you can farm a dungeon?
And going by your logic, if trying to optimize your raid is cheesing, isnt it kinda stupid going for 75 Percentile logs? Because that means you are limiting yourself and your class. Why dont you use Looking for Raid Logs for healing? Easy, because one good healer could replace those 5 random healers and even then - looking for raid wouldn´t be enough to actually challenge his capatibilities. That is basically what you are doing when you are looking at 75 percentile logs. You are looking at players and classes that COULD do better but dont do it because it isnt necessary at all. So tell me, when there are 4 healers, everyone needs to do 300k hps to keep the raid alive and one healer is doing 350k hps because of heal sniping. 2 of the others are doing what is asked of them and are doing their 300k hps. So what about the fourth healer? Should he still be going for 300k hps even if it involes unnecessary overheal and doesnt bring any benefit at all? No, he will do 250k hps because that is everything he needs to do. Is it really a good idea for trying to measuring your class by that? No it isnt.
When comparing DPS and HPS you should go for the maximum, because that is the only indicator that can show us what we COULD do if we need to do it.