I used to feel this way, until I had the realization one day that almost everybody I know in fact refrains from using their phone even during group interactions

I used to feel this way, until I had the realization one day that almost everybody I know in fact refrains from using their phone even during group interactions. I felt the way you did because people don't use their phones around me in general, so I never had the opportunity to be overly upset about phone usage in the first place, nor did anyone else. Of course there might be the occasional checking of messages, and nobody minds that, especially in groups. But generally I've found people in my age group (early to mid 20s) to be very mindful of when and how they use their phones. If they are going to text in front of you, I find that they often explain out loud why they're doing it, without your even asking, so you know that they actually are responding to something that needs or deserves a somewhat prompt reply. The illusion was shattered for me with my former roommate, also former friend. I was really amazed at how he'd just sit on his phone on Facebook whenever we went out together to grab something to eat. He'd often just sit there in silence. What sealed the deal for me and led me to the above realization was how he'd ignore me even if I remarked on something while he was in the midst of his Facebooking. It was so offensive to me that I don't even consider him a friend anymore.