Sure, Bowser may be spiky and have a face only a mother could love...and he committed war crimes several times...and can't take no for an answer...but under that spiny outer shell lies a romantic, caring ruler. Probably. For all of his bluster, the Koopa King's minions genuinely respect and admire him and he's a good father to his son. Even the main Super Mario cast seems to recognize this: why else would they bother inviting the neighboring warlord to go-kart races and tennis? Peach might be missing out because as far as players can tell, the tyrannic turtle has a lot of stuff to offer that Mario doesn't...as long as she's willing to look past the kidnapping and attempted murder and not being human.
Source:https://www.cbr.com/bowser-would-be-a-catch-if-he-wasnt-a-turtle-dragon-evil-overlord/