Why and how is it out of control? People are out walking, socialising and doing something which they enjoy whilst not impacting others*.

I fail to see what people could have against Pokémon Go.

* I am sure that the response from some will be that it's annoying to have people walking into you and/or suddenly stopping whilst playing Pokémon Go, however I have not experienced this; I have experienced tourists just stopping dead in their tracks and business people checking their e-mails and walking into me, but no Pokémon Go related incidents so far!