For a marksman exhaust seems like the better dueling option and heal on a support would be better with the amount of supports that take ignite with grievous wounds only affecting self healing now and it would benefit from windspeakers. in teamfights marksmen will save heal for when they need it but a support can use it freely to save someone from damage.
Shipwreck3 votesI actually tried this with a friend a while ago, it works pretty well when your in communication with your partner
Prozzak3 votesBecause heal used to only heal half for other people. Really this is what should happen nowadays (back like in season 2/3) but people are stuck in their ways now so they won't change back to what is (imo) better.
JayHog19923 votesI always do that when playing Lulu with windblessing since the heal becomes stronger and gives the adc the bonus of the mastery.
Aeolian Melodies2 votesBecause supports go in for the offensive play so the combat spell (ignite or exhaust) being on them makes more sense, and ADC being able to chose when the heal is used is more practical.
Sneakyy XD1 votesBecause the only time you want to heal the support is in the lane when no other target is available
Banshee1 votesThe reality is, you are not always going to have your support by your side as an adc. Also as an adc, the enemy team wants your booty, so you will often find yourself getting jumped on by multiple people. Since exhaust is a single target summoner, heal allows you to fight with more health and gives you a movement speed buff to re position yourself and kite he enemy better. In a perfect world where the adc and support are butt buddies, then in theory it doesn't matter who takes heal or exhaust but we don't live in a perfect world.
Ionian1 votesBecause as the ADC you usually won't have time or be in range to exhaust the enemy assassin / mage oneshotting you.
Squ1zzle1 votesI think it all falls down to adc'd are what league of legends calls marksmen. Its kinda like taking ignite on Xerath. The range of the adc is farther then exhaust so in order to click the target they have to walk into it instead of kiteing. The support is one the one that is trying to interupt the enemy champion so it makes more sense for them to have the exhaust being the one standing right next to the enemy. The adc only has to worry about clicking heal for that burst of health that keeps them alive. Not clicking exhaust on someone and getting themselves to close to enemy champs.
Lovely Pants1 votesNot sure what the official statement of the hive mind is, but I'd guess the following things contribute.
Carries often don't want to be in range to use exhaust to allow them to use it flexibly. Heal provides more general death prevention. The mobility boost from heal more reliably benefits the player using it. Being able to reposition easier late game is very important for carries. Late game heal is not as useful on supports as exhaust to save allies.
And such things.
Exhaust isn't straight up bad on carries, in any case. Heck, something like double exhaust might even be more useful in niche cases. Heal is just a very generally applicable and flexible defensive spell for carries.
ValyrianBlade1 votesMostly because an ADC can heal-bait, while a support can't really.
If you think you can burst kill me, but I have heal as an ADC so you can't, then I have enough sustained damage (and late game lifesteal) to get the kill on you. I may not have the reflexes to exhaust you before enough damage has come out that it barely matters.
If you think you can kill a support and he heals, what's he going to do? Hit you with a wet spaghetti noodle a few times before it wears off and you kill him anyways? :P
Also, as an ADC I'll often be focused early in a fight. I may receive peel at some point, but since I was focused I took damage early. So if an ally is almost dead in a teamfight I can heal and we'll both benefit. Often supports are ignored in the early stages of a teamfight, so if they heal for an ally they'll waste the self benefit.
