Rules, tribes, society and simplicity.

Before the formation of big societies, rules were simple. They were suited for tribes, their plain hierarchies, and the limited number of their members.
As these small groups developed into bigger, and more complex communities, the need for more control over these diverse populations increased.
To be fitting for larger congregations with different lifestyles, these regulations went from being very specific to being very general as they tried to fit the large group rather than the individual.
Their general nature of these regulations made them rigid, which forced people to come up with shrewd alternatives to bypass them.
A large number of commercial transactions still take place within communities, and families. These alternative “markets” have very simplistic unwritten, agreed upon rules, they are all based on trust.
Not so long ago, a handshake was enough to seal a deal, saving a lot of time and resources, and making our lives a whole lot easier.
Within close-knit circles, namely, family and friends, people don’t expect written contracts, stiff clauses, and outrageous default penalties.
When the needs of these small groups could not be met by their own communities, they ventured outside, where more complex societal rules applied.

With the spread of individualism especially in western societies the general rules govern daily affairs since communities tend to be fragmented or sometimes completely inexistant.