Yes. I believe Robert Heinlein said it best.
"Sick cultures show a complex of symptoms such as you have named...But a dying culture invariably exhibits personal rudeness. Bad manners. A lack of consideration for others in minor matters. A loss of politeness, of gentle manners is more significant than a riot.
America, btw, exhibits all of these symptoms.
I'm not sure why anyone would argue against that, save for more hardcore moral nihilists like Envisage.
I agree that children need to learn discipline, respect, propriety, restraint and so on. Humans are not beasts; we are social animals and these rules glue society together and keep them from falling apart. Nor are they high expectations - in fact, respect for others is innate, and we only have to develop that to be capable of propriety and restraint.
Moral Decency is important. Indecency can lead to detrimental thoughts for children, and therefore the next generation. If kids were exposed to improper material, their mindset would adapt to it. Every person, especially children, must learn the value of discipline and respect. Being proper is one thing. Restraint is another. A society that is morally decent is a society that is contrary to a society of moral rot.