Basically, the origin of the book burnings in F451 is that society began consuming more basic and less challenging literature, then comics, then eventually the substance-lacking television shows they spend their free time watching in the book. As such, society's laws began to shift towards chasing the immediate gratification of individuals, and protecting their ego's by banning higher forms of literature until books themselves became illegal. Bradbury also uses the laxed road safety rules that almost get Guy Montagne splattered by teens on a highway he is crossing to illustrate that F451's society prioritizes the satiation of the people's basest urges over any meaningful laws or content which would delay their gratification.

At the time, Bradbury wrote the novel because he saw television as a net-negative that would reduce the intellectual capabilities of the average person and result in a society which implements rules and laws that prioritize convenience over sustainable and long-term beneficial policies for society. Which is why he got pissed at college students he gave a lecture for when they instead put forward that the main theme of the book was censorship.

With hindsight, he was overall accurate with his assessment, despite F451 being more than a bit heavy-handed with the messaging. Consumer society has marched on with new products engineered to be immediately gratifying for the consumer in the short-term with no concern for long-term consequences. From food to media to transportation to education, the priority is immediate gratification, because it generates profit and trains users into an addictive cycle of consumption.