I admit that I, too, have a visceral reaction to that bastardized pronunciation. I remember rebuking @Ben Ruset when he committed that sin some years ago. I can only hope he has since changed his ways.
I live on Atsion and have since 2013. Grew up in Barrington. I always say At see in. I was made fun of by some locals to the point I now try to say At si on but I always slip up. It is def the way to tell people who grew up in area vs people who moved here.
I neglected to mention while we were discussing Atsion last month that I've had special linguistic training that gives me great confidence in my pronunciation:
I admit, these mentors probably explain a great deal about the level of intelligence and sophistication I demonstrate in my NJPB posts.