Not quite sure what point you're trying to make here, but I think I can explain why the whole world is having so much fun rubbing trump's nose in this particular failure.
I'm sure we've all known that person who is way too impressed with themselves and loves to tell everyone else about it. The person who thinks they're the smartest, fastest, strongest, bravest, most charismatic person ever, even though they're really not all that impressive. And we've probably all thought about how satisfying it would be if that person ever got a dose of reality to bring them down a peg or two.
trump has been that person to the entire world for the last 4 years. Despite his history of abject failure, nothing but shitshow after dumpster fire, he gets up on his stage and tells everyone how successful he is, how much he's done, and how nobody has ever come close to being as tremendous as he is. Well he finally just got his dose of reality. 6200 misguided Americans showed up to lick his boots, when he was expecting quite a lot more.
That's what makes this so satisfying. This absolute failure has been blowing his own horn on the world stage for so long, and getting away with it, despite failing at his every endeavor, at the expense of so many that he's supposed to be working for, that to now finally see him publicly forced to suspect that maybe he's not as great as he thinks he is, if only for a second, is cathartic to the majority of the people, who have had to sit through so, so much of his self praise and adulation.
Suck it trump. You're a fraud, a failure, and an absolute moron, and everyone can see right through you.