User blog comment:Deshiba/Heal on supports/@comment-1330314-20170323062958/@comment-8506165-20170324145637

" it's much better for the marksman to have a self-heal and movement speed boost to use exactly when they need it."

Additionally, contrary to what some people seem to think, supports aren't shackled to the ADC for the entire game. If I'm playing a beefy support who wants to start fights and dive into the enemy, I'm not going to be in Heal range of the AD if they get into trouble and need the movespeed from it to kite, even if I know enough about ADC to know exactly when the appropriate moments to use Heal are.