Questions to those who disliked the film

I happened upon this film this week. It came recommended along with 'Starred Up' a more recent UK prison film.
Ive been reading quite a lot of negative reviews and wondered if the majority
of those who disliked the movie are American?
Reason I ask this is because ive seen people saying this is not realistic.
This movie is NOT about gangsters. It's about youth gangs and here in the UK
that's exactly how young idiots DO behave.

Once one understand that this movie makes more sense.
So much in the same tradition as 'Scum' this movie is a look at small time
youth criminals. For my penny's worth I think Joe Cole did a sterling job
playing the vengeful youth, and also felt that Frank English played the
annoying ''big time moron' role very well he was supposed to be a character
that annoyed the viewer and all his faux hard man front wasn't over acting at all,ive known real idiots just like the one he portrayed. Id be willing to bet
Frank English based his performance on people he's known growing up.

Anyone else agree?