Originally Posted by Roku
I'd be a bit hesitant for a purely passive Summoner Spell...because clicking buttons and seeing effects is a really fun thing. You lose gameplay and balancing levers when making a purely passive spell (cooldown, uptime, etc)
However, Heal might gain a purely passive component to slightly benefit the person that picked it.
I believe (fully) passive summoner skills would add great variety to builds. Also I am sure there are people who would, at some point, be happy to give up on two extra skills (which would also ease the pressure - two less things to think about) and isntead get a staedy, consistent bonus(es) in-line with their playstyle