Finally, someone else noticed.
The beginning of the bro-country era can be pegged to mid-December 2012, when Florida Georgia Line displaced Taylor Swift at #1 on the Billboard Hot Country charts, stayed there for five of the next six weeks, and then crushed everything from mid-April to Labor Day 2013. There were songs earlier in 2012 that were harbingers — notice that there were #1s called “Drink in My Hand”, “Drink on It” and “Drunk on You” — but the sheer dominance of BABY YOU A SONG signaled change had come, and not for the better. (It gets worse; FGL has had the current Hot Country #1 for seven months.)
Were there allusions to drinking before? Sure. But the singers didn’t build their style and empire around it. That was, until Kenny Chesney decided he didn’t want to leave the beach, and opened the door for groups focused on drinking and trucks and women and drinking in trucks with women.
The headline on this 2015 story sums it up: “Bro-Country Is a Plague, and Florida Georgia Line Is Patient Zero.”