Not to get too high-horsey, but we have quickly morphed into a society where everything is for show. You go on vacation and are as invested in the photos you post on social media as you are in the experience you are having with your family (using the "royal you" here, I am certainly not immune). You score a TD, and you are more focused on performing your pre-planned dance routine than in celebrating with your teammate who is rushing up to congratulate you. You earn a big victory, and you are more concerned with making a viral moment by rubbing your opponent's face in it than in celebrating what you have accomplished with your brothers.
I am on-board with most asshattery that takes place between the whistles, including trash talking and a bit of showboating. I am okay with exuberance, and fun, and TD celebrations. But there is a line, and it is a fuzzy one, between having sincere run/revelry vs. a self-centered focus on creating a brand.
I am NOT on-board with things like skipping the hand-shakes or flag planting. You fight like Hell between the whistles, but before and after the game you should respect your opponent and the work they have put in. It is also silly to get too upset about these things, you cannot control the behavior of others, only your own. Be confident in who you are trying to be, don't get caught up in how others choose to behave.
I try to remind myself that my values are not necessarily the right values, and if someone else's differ, that doesn't make their values wrong. Most of us grew up pre-smart phones and social media. Go back to your middle school self, but give yourself the power to instantly photo or video yourself and distribute it to the entire world with a few clicks. That would blow your 12-year old mind, and it is no wonder culture is shifting in this direction.