No, I very much do not like Djokovic, but the heart reaction is simply because it's an awesome surprise: a player from outside the top-100 beating one of the players who always win the big events, I don't see how that isn't cool
Same with the Grand Slams in the past eternity or so. The wins of Sinner, Alcaraz, Medvedev, Thiem were awesome, instead of always Djokovic, Nadal or Federer (and the hype that goes with it, that always goes along the lines of "wow, Nadal/Djokovic/Federer wins historic 532th Grand Slam title, he is for sure the GOAT!", year after year....you know, media people, at some point it's just not special anymore).