The problem is we can't enforce the current limit. Most drivers caught are caught at Christmas or after they crash. Not really enforcement.
The current limit is ineffective and not policed. So how would a change in a limit have an impact?
I am not suggesting that the Police never carry-out spot checks, but they are apparently rare enough to allow too many people to habitually drink and drive and never get caught (unless they hit someone obviously).
May be useful for you both to do some research before making erroneous statements about the level of enforcement.
The stats are readily available online from official government sources.