Czech republic is pretty liberal (conceal carry, attack rifles...) and we have lower crime rate than UK.
> I don't really understand why people are so against having some gun control
Problems:
1) not everyone lives in a big city, where police is on every corner. In remote rural areas it takes hours before cops even arrive. Some people simply need gun for living.
2) Regulations always get more strict over time. Eventually everything will be banned (knife, pepper spray...). In UK it is illegal to carry a screw driver on street.
3) People are motivated not to report crimes. There was a case when girl escaped a rape, but was charged for possession of illegal weapon, and for using a pepper spray on her attacker. With regulations, it would be best for her, not to even report that attack.