People have hit on most of the main points better than I ever could, but I want to mention that personally I feel the vast majority of gun control schemes are intentionally misguided, not to prevent shootings, but to punish gun owners for some perceived slight against them. I grew up in a very liberal part of the country, in a very liberal family, and hated guns up until just a few years ago. The thing is - subtly or not - you're taught in this environment that 'gun owners' are all fat, racist, ignorant inbred violent murderous assholes. Go look up some anti-gun political cartoons and you'll see caricatures there that go beyond just satire into the realm of honest-to-god offensive. If you made a political cartoon about black people with big lips, colored pitch black, eating watermelon and oggling white women, you'd be crucified - not just because being black is a "protected class", but because you're being deliberately hurtful, and you're perpetuating stereotypes that have damaged that demographic.
It's tricky to bring up what my point is because every time I mention it, some asshole goes "LOL YOU'RE COMPARING OWNING A PENIS EXTENSION TO BEING BLACK LOLROFL GUN NUTS GONNA GUN NUT", but my point is that even for things that aren't "protected", there's always a line and if you cross it you're an asshole - and as a gun-hater turned gun-owner, I think a lot of the left's demonization of gun owners has led to a feeling of "gun laws are a good idea, because fuck gun owners". It doesn't matter if your silly law works or not - you pass the law because 'fuck them'. Do you really think politicians don't realize that banning bayonet lugs doesn't do anything? Of course they realize that - they pass those laws because gun owners like those guns, so fuck 'em. They don't vote for 'our people', they aren't 'our demographic', they don't live in 'our districts'... they're the enemy, and we're at war.
Like I said, I grew up in that mentality - it's still alive and strong. It's funny how the same groups who will talk about our 'violent culture'... Salon, MoJo, HuffPo... are also the same groups who want to encourage people not to just disapprove of gun ownership - but to hate gun owners. I mean, look at this shit. Or this: "They stalk you and ambush you in the dark outside your home".
This is all a really roundabout way of getting to my point: The reason I dislike gun control is because implicitly, gun control schemes are a violation of my fifth amendment rights. When someone buys alcohol - even if they're buying a funnel, a clamp, and some 1" tubing at the same time - there is no 'binge drinking' check or ban to stop the sale. The societal agreement is that you can buy alcohol, but do so responsibly, and that most people are responsible. Those that are not are ostracized and their actions are THEIR fault - no matter how drunk you are, inebriation is not a defense and it's all your fault.
When it comes to guns, the implication - the overwhelming number of faulty / pointless gun control laws - is that I am the perpetrator of some future crime, and the state should do everything in its power to stop me before I commit it. Not only is this insulting but also an infringement of not one but two of my civil rights. This doesn't mean that I think there should be zero gun laws at all - rather, I think there should be a very, very strict level of scrutiny applied to any and all 'malum prohibitum' laws like that, and that any law must have a justifiably provable positive impact, and must be implemented in a way to restrict civil liberties as low as possible. This is the same standard the SCOTUS applies to most every other law - except gun laws, which they routinely refuse to pass judgement on.