I think there's two kinds of millennials. There's the millennial that grew up before social media/smartphones and the millennial that grew up with social media/smartphones. The former seems to have better social skills than the latter. I've told this story before, but my original career of choice was journalism. I went to school from 2004-2008 then went back to school to get my MBA in business management from 2010-2014. The difference in millennials from those two time periods is night and day.
During my first foray into higher education, kids actually talked to one another between classes. We got to know each other. Talked about where the party was at, if we were going to the show/concert/game/etc. We talked about the class, the teacher, everything. We had nothing else to do.
My second foray was a LOT different even though the years weren't that far apart. But it was something I could start to see happen at the end of my first attempt. Now, instead of walking down the halls and hearing kids talking to each other, their heads were buried in their cell phones, laptops, tablets, etc. The halls between classes were much, much quieter. It was like they lost the ability to talk to one another.
I often interview millennials a lot for some of the entry positions in my company. While some genuinely do have good social skills and common sense, I've come across others that were extremely awkward socially (moreso than some of the Gen Xers and Boomers I've interviewed). I also cannot tell you how many I've interviewed that have either: A) shown up without a resumé or, B) have worn jeans and a button down to the interview. That's something I have NEVER seen from other generations.
That said, other generations suck just as bad. I have never seen either the Gen Xers or the millennials present the same massive sense of entitlement and "I want it now, now, right now!" attitude that Boomers possess. The Boomers are also directly to blame for the state this country is currently in since our elected representatives are mostly from that generation. Further, it's absolutely hilarious to hear both generations criticize the millennials since they're the ones that raised us. We didn't raise ourselves. Bang up job, guys.