My friend Bob Shanteau writes:
Another reason scofflaws give [to justify their behavior] is that traffic laws are intended only for motorists, reflecting a total ignorance of the origins of those laws.
Google has made the 1909 book “Street Traffic Regulation” by William Phelps Eno available online.
This book makes it clear that the first rules of the road preceded the dominance of the streets by motor vehicles. The behavior of … scofflaw cyclists now closely mirrors the behavior by all road users that Eno observed in the early 1900’s, leading to the need for street traffic regulation in the first place. He focused his efforts on education about his proposed rules of the road. That education is what the bicycle scofflaws of today sorely lack.