If you live in the states, then that is probably true since most manual drivers tend to be somewhat enthusiastic about cars over there. But a majority of all manual drivers don't live in the US.

Here in Europe, a vast majority of cars were manual still a few years back (still are I think, but almost all new cars are auto nowadays), which meant that everyone including your wife and granny (literally) were driving manuals. Which means that most manual drivers were the type of people who see cars as a mandatory but boring appliance. These people don't know how to rev match, let alone heel-toe.