It's not just social media. There are more combines, football camps, etc. These guys get to know each other, play on the same teams, etc. It's hard to hate a guy when you've play with them or you're competing for the same goal.
I don't think it was as abundant in years past as it is today.
Interestingly, my son played 7on7 football with a team that included guys from different Southeastern states. We played against some of those guys during high school football, and the tone was different because they played with each other during the summer.
I personally have no problem with the new approach. It's not like guys are not going to hit you or not going to do their best because they hang out to eat. They're professional enough not to divulge team secrets.