I think you mis-read the OP. He is not asking whether of not gun-control laws make sense. He asked, assuming that there are in fact going to be (or already are) gun-control laws, why are they not enforced?
There was probably an assumption that we would know what he is referring to – but I don’t. From the question and CTL’s response I am guessing that some law was proposed that is un-enforceable or will purposefully be looked away from to allow things to continue as is but to nevertheless have the law ‘on the books’.