i find it hard to particularly enjoy movies where none of the characters are likable or relatable in any way, and actually somehow get worse with the progression of time, leaving me to wonder at the end if they were supposed to be so or not
i would have been completely cool with it if there were some comeuppance for his psychopathic choices. but there wasn't. ellen page takes a bullet to the head, but she'd already established herself as even crazier with the rape scene so i was glad to have her gone. his motives are even justified around that time too, when they haphazardly shove in the scene where kevin bacon sells liv tyler to the drug lord. frank doesn't get the girl back, but he expresses that it's a positive thing.
I would say the main guy is pretty relatable as an average person who is sick of seeing injustice and crime. Obviously not to the same extent but still.
Also, his face for most of the criminal beatdown montage is priceless.