Side comment about me using fb

One time during class (school in the USA), I used the spare time to scroll over facebook (website version) with my laptop. Some guy (he was white, idk but I think it's quite a relevant detail) commented to the rest of the people of the table:

"You know, the only 2 types of people who use facebook are either boomers or from a 3rd world country."

(I'm from the Philippines). Random comment really, there was no prior discussion regarding any of the sort before the statement so I was just surprised why the sudden remark. I wonder if that was purely declarative or there is some undertone I am glossing over. (the reactions from the rest of the table were also awkward laughs). He's quite true though, we are very chronically online, and consistently place in social-media usage rate indices. (I wasn't really offended but I thought it was a weird enough encounter for me to share in reddit).