[Swizec]

It also made the behavior socially acceptable. "So many people are late that we introduced a fine"

"Oh phew, it's not just me. Everyone's doing it"

[netsharc]

But also, you'd feel guilty for making people wait for you, but with this you'd just think "Oh I won't make it in time, but no worries, it's just 5 more dollars [or whatever the rate is]."

[elastic_church]

also turns into a cost benefit equation, instead of a mere cultural/etiquette one

[ionwake]

Bingo