The number one reason for me is understanding what bitcoin is. If you are new to bitcoin just like me, you won't get how exactly it works just by reading. You need to learn the terms in order, I mean the first thing a new user has to learn is how to have a bitcoin wallet ( I mean if you read about ASIC or hashrates, etc. first before bitcoin wallet, you would not understand it right . It's not the price that's stopping people to use it, actually if you tell them 1 bitcoin is equal to $370, it would spark interest. The reason people stop using bitcoin is that it's hard to earn it(I mean you can't use what you don't have).
you can buy bitcoin and i don't think it's hard. signature campaign is a not so hard way. or start with faucet, it's very easy, a good start for newbie, many people believe that.