I always found funny throwing a sticky grenade into a grunt, only for him to go running like crazy (and generally into his teammates, which result in a win/win situation).
The other option is to have all AI 's that get stickied, run into you. And than the game is automatically hard. And people would start rage quiting. And making bad reviews. Like the grandes being worthless. Since you couldn't use them, unless you had cover. So AI's are probably gonna stay dumb to a degree.