Some language and tool cultures have a very high
CostOfLearning. Oracle, Java, C++, Vim, and anything for which there is a certificate beginning with the letters MS come to mind. Others have a lower
CostOfLearning - present winner is probably Ruby.
CostOfLearning is related to whether the culture is
ExtremelyInterstrangled and consequently whether its underlying language(s) have much
SymmetryOfLanguage.
What other factors are involved?