Recently, I've run across people adovcating for long command line arguments. This got me thinking again about a paradox I've observed.
On their own, long command line flags are more readable. However, I find that often, programs that opted into long command line arguments far less usable. Programs that restrict themselves exclusively to single character flags tend to be easier to learn and remember
Lifting the restrictions and making an effectively infinite number of flags possible means that a large number of flags get used, and a large number of similar, rarely used options get added, just in case.
The small number of characters available in the alphabet seems to force authors of programmers to think harder about the flags that they are implementing. This results in more usable programs.
As often happens, restrictions shape a culture, and cultures strongly influence usability.