I want to know what the writers were thinking when they made the obvious wife beater bob with fire powers a prominent character

Even if this is quite immoral, I think if our world had the setting of quirks the same would happen here; so it is good to include it and show what mental corruption power can cause. It also creates the possibility for a redemption subplot later on (if such redemption is acceptable is up to the viewer).

I can’t really say the same about the villains however. They feel very one note and feel like they only exist to give the heroes something to punch.

Agreed.