Why does Dio act like an asshole from the very beginning ?

[keen jetty]

Wouldn't he become rich and powerful by being nice to the Joestars ?

[flint burrow]

he doesnt want to be nice to the joestars

he wants EVERYTHING

[solar plover]

That's just how he is

Hes meant to represent evil

So he's evil for no reason

[blissful trout]

cuz he just a hater like that

[ashen oak]

Well thats just how dio is, hes a psychopath, he wants everything. Even before he was adopted this guy poisoned his dad.

[keen jetty]

Unreasonable evil

That's goofy af

[crude gust]

Because he's an asshole

[lethal socket]

Dio grew up very pour and then he meets Jonathan who's grown up very rich so combine dios pettiness with his power complex and he automatically despises Jonathan because he hadn't faced hardships like he had.