Nobody's saying that... You're just going there.
The OP said training isn't a MUST. I disagree. I'm not saying training must be mandated and courses taken, but as a responsible person, you need to train with a gun and gain some level of proficiency. Buying one and tucking it away, never to be touched or trained with, is a bad idea on the gun owners part.
With all due respect, the individual citizen has the right to keep and bear arms, which includes obtaining a firearm "and tucking it away, never to be touched or trained with". The manner in which one citizen chooses to exercise his rights is not subject to any influence by another citizen. This troublesome point appears to be the real crux of the whole gun control debate; some folks seem to think that other folks need to be subjected to the legislative and/or regulatory control of the majority, as expressed by the legislature and the executive.
'Rights' are certainly not absolute in nature. One's right to free speech does not entitle him to shout "FIRE" in a crowded theater, or to make libelous publications about another person. One's right to free exercise of his religion does not entitle him to demand the participation of others. One's right to keep and bear arms requires no permission from his neighbors, or the government.
The citizen who buys a gun then "tucks it away, never to be touched or trained with" is certainly not engaging in the most thoughtful and responsible approach. However, that citizen has not engaged in an inherently irresponsible approach, as the gun that is never touched cannot do any harm to anyone. Further, that citizen is better prepared to act in self-defense than the citizen who never acquired the means in the first place.
Every element of the debate over "gun control" is an exercise of logic versus emotional response. Promoting "common sense" legislation and regulation is easy to do by playing on peoples' emotions. The problem lies in the slippery slope principle; once a small restriction is accepted there will always be a greater restriction coming, and over time the whole concept of a citizen's rights is lost. And once one right has been effectively erased all other rights become vulnerable to the same treatment.
Training requirements, safe storage requirements, background checks, restrictions on firearms types, magazine capacity restrictions, caliber restrictions, permit requirements, licensing requirements, transportation restrictions, open carry laws, concealed carry laws, and many other means have been used for decades to incrementally strip away the rights guaranteed by the Constitution.