@16: Liar liar. Of those 80,000 instances nationwide in 2010, there were 44 prosecutions, not 0. And not all of those 80k constitute a crime! Providing inaccurate information will get your application rejected, but it's only a felony if it's deliberately done. (source
As far as enforcing additional laws goes, wouldn't universal background checks be exactly that? I mean, we have laws saying that people with XYZ criminal record can't legally own guns, but there's a loophole that prevents the laws from being enforced when the seller isn't a federally-licensed dealer.
We actually DO "[check] that someone is legally allowed to vote". What do you think they do with voter registration forms? Just rubber-stamp them? No, they verify that the applicant is eligible to vote. Requiring photo ID also at the voter booth would be like making a gun owner pass a background check every time he gets his pistol out of his gun safe.
And seriously? Your first sentence? Do you REALLY think other Constitutionally-guaranteed rights don't have reasonable restrictions on them? In order of Amendment in the Bill of Rights:
I. Speech can be restricted if it incites violence, is slanderous, involves the theft of trade secrets, causes a breach of the peace, or similar. Classic "fire"-in-a-crowded-moviehouse stuff.
II. The right to keep and bear arms is contingent on not having a record of violent crime or severe mental illness. Cry me a river.
III. Soldiers can be quartered in private property during wartime so long as it's authorized by the legislature.
IV. Searches can be conducted without warrants if there is probable cause or if there is a credible and immediate threat to public safety.
V. You can be compelled to testify against yourself if the testimony consists of documents or other already-extant information rather than simple speech. The Miranda warning can also be skipped if there is an imminent threat to public safety.
VI. The right to a public trial is not absolute, for example where issues of national security are involved or where excess publicity is disruptive to the proceedings. The right to confront one's accuser in court doesn't apply if the witness was killed or otherwise incapacitated to prevent them from testifying, or if the witness gave a "dying declaration" regarding the circumstances of his own death.
VII. Actually pretty much without exception, due to the brevity and straightforwardness of the text.
VIII. Excessive bail or fines are subjective; there is no hard-and-fast guarantee.
IX. Again, too brief and straightforward, not to mention abstract, to have any exceptions.
X. The federal government has a lot of leeway in making issues part of its jurisdiction. There's a lot of judicial precedent, for example, supporting the federal power to regulate the production or sale of commodities within a state based on the rationale that it affects interstate markets of the commodities.
Rights are not absolute and unlimited.