People criticise limping often. And its usually a thing to mix up your play to help disguise your hands.
But in general, when is it okay to limp into a hand, and is it worth it long term?
For example, KJo or K10o is a typical hand that I might limp with from almost any position. If i decide to play this hand I probably limp with it 70% time and raise 30% of the time. I might even call with it if I suspect someone has a small pair or a weak ace.