These trends in writing and society do wax and wane. A plain style emerging in the Age of Enlightenment, a period with social movements that valued rationality. A more prosaic style can reemerge in a response to perception that such rationality can be too cold and austere, such as during the Romantic movement.
In our era we see commercial oriented speech dominating all communication. A style that communicates concisely while also misleading the reader. Modern writing styles attempt to engage the most basic needs and feeling in order to elicit an emotional reaction in the reader. Commercial speech does not want rationality. Disrupting the conscious decision-making process is the goal when it comes to getting a consumer to buy.
And because commercial speech dominates television, radio, and the Internet. We have generations of people in the West who from a very early age primarily experienced English as a language used to manipulate and sell them something.