b) 90% of Americans don't "do" traditional carpooling and they're not about to start
90% of Americans didn't pay non-professional strangers for a ride before Uber came along. 90% of Americans didn't share what they were having for lunch before Instagram. 90% of Americans didn't share the hilarious list of "cats who forgot how to cat" before Buzzfeed.
The point being it's pretty much impossible to predict what product will be a success based on past market behaviour. Saying something won't work is very often right, but it's a sucky reason not to try.
90% of Americans didn't pay non-professional strangers for a ride before Uber came along. 90% of Americans didn't share what they were having for lunch before Instagram. 90% of Americans didn't share the hilarious list of "cats who forgot how to cat" before Buzzfeed.
The point being it's pretty much impossible to predict what product will be a success based on past market behaviour. Saying something won't work is very often right, but it's a sucky reason not to try.