Remember that episode of SpongeBob when Plankton says to Bob to be assertive? He wants SpongeBob to be like Bakugou.
Bakugou is your asshole co-worker who wants to get to the top of the company, does his work constantly, tries to one-up everyone constantly, but still plays within the rules, is unapologetic and doesn't give a single fuck. He also constantly makes fun of your lunch.
And he is as good as he says and that just makes you hate him more.
People like this exist, they are unlikable but they can be awe-inspiring too, in a twisted way. Its also the perfect foil to Deku. Honestly Bakugou would be incredibly cliched as a villain, but as a Rival and aspiring "good guy" he keeps subverting our expectations.
Also lets not forget than in this world been a Hero is a Profession, on the level as a high paying goverment work or acting career. It attracts all kinds of people, even assholes.
Honestly most people who defend Bakugou don't "like" Bakugou, but we love to hate him and how he inspires the rest of the class to try and beat him almost out of spite.