Aegon Targaryen, now King Aegon II (Tom Glynn-Carney) could never really compete for the title of the most evil character on House of the Dragon, thanks to pettiness of his bad deeds.
But for three and a half episodes he was portrayed as human garbage with hardly any depth and no redeeming traits whatever.
Naturally, comparisons with Joffrey of Game of Thrones, another royal brat who was meant to be a hate sink and succeeded in becoming one, started to arise.
Now, even back then the differences were noticeable.
Joffrey in the TV series came off as a naturally twisted man, who was never significantly mistreated, yet still grew up to be a serial killer. He also appeared practically asexual, never drank to the point when that could excuse his behavior, and could feign normalcy when he had to.
Aegon, after outgrowing mean childish pranks, was only thinking of wine and sex with everything that moves, lacked in ambition, and was quite incapable of presenting a pleasant façade. But the similarity of "this Prince is here to be despised" was obviously there.
However, much, possibly most of the fanbase have changed their minds since Episode 9.
While it credited Aegon with more odious acts, it also made abundantly clear that not even his mother Alicent cared about him beyond the political value he had (earlier episodes already heavily implied that King Viserys did not love his children from Alicent at all), and that Aegon was at least self-aware about being a shitty person who's unfit to rule, even if his attempt to escape from it all was childish and stupid.
And then came the coronation scene, with much-praised acting of Tom Glynn-Carney, showing us Aegon's visible change of attitude, as for the first time in his life he gets praise and adoration – from the cheering crowd.
While it is not likely that this transformation is going to change Aegon for the better (the showrunners still need a designated villain on the Green side), so far events of Episode 9 won him substantial sympathy from the audience.
The prevailing opinion seems to be less "this little bastard needs to die" and more "Westeros might have avoided all the upcoming civil war if only poor Aegon was allowed to drink and whore as much as he pleased, instead of being pushed onto the throne" or at least "well, he's weirdly entertaining".