Paul Fussell, in his work The Great War and Modern Memory, referred to the high or elevated diction often favored by writers, both professional and lay, at the time of World War I. A horse was a steed, a friend was a comrade, the dead are the fallen, to conquer is to vanish, bravery is valor, a draft notice is the summons, and so on. This language survived the Great War, as World War I had been called before an even greater conflict happened over twenty years later.
In a similar vein, The Great War marked the end of the belief in the inevitability of progress, the superiority of Western Civilization, and general cultural optimism. The 1920's were the era of the Lost Generation.
The language of a later time was studiously lower diction: chipped beef on toast was shit on a shingle, unnecessary harassment was chickenshit, and so forth. I remember my dad referring to the discharge button issued to all American participants of World War II as "the ruptured duck." Clearly, this was a generation that took itself less seriously.
Or did they? They wanted to live and prosper as much as their fathers or grandfathers. It's just that they had a different cultural ethos than the earlier time. And this attitude continued to the present time.
Alainis Morrisette did not develop irony in the 1990's. It antedated her. She, like us, were influenced by this cultural shift. Can anyone seriously believe that wars might be fought to make the world safe for democracy? Screw it. Nikita Khruschev said, "We will bury you." He meant it. Literally, not philosophically. The Cold War was waged for survival.
In 1940, Benjamin Lee Whorf introduced his linguistic relativity hypothesis. In its strong version: language influences thought. High diction championed adopting a view of life as potentially elevated, meaningful, teleological. Of course, the opposite can hold true as well. A danger of dysphemisms is that they degrade what is referred to. And they may make chipped beef taste worse than it really is.