What's with the 'non-channeling skills' modifiers?

Literally just want to know. I see it pop up here and there in the game but now it's included on a whole two notable branch of an ascendancy. I want to understand this player choice limiting mod and maybe I will find it a little less frustrating.

Think it's to prevent stuff like minion pact + hourglass + consume power charge for 'more' damage + channel incinerate forever.

I'm guessing some of the new support gems will be specific for "Channel spells only"