It does not show the failure to provide for people with mental illness, because that isn't discussed and we only see 2 references to it when he's in hospital.
The dialogue is garbage, it doesn't even make him look as if he has a metal illness it just makes him look stupid.
Simon Pegg was the wrong choice for this anyway as he simply has not got the acting range to carry a role like this off. Juno Temple was the only good thing in the film: she is always awesome in anything she does.
I gave it a 4 just for Juno Temple, nothing else in the film deserves a thing.