Smart people should know how to keep their money. I think we talking about safe keeping, so not jist exchange site, there is other services that can easily crash in some moment. People should be ready for worst situation that can happen, that way everyone will try to protect their money in best possible way. I think its not hard to spend 10 minutes and download some good walllet, that 10 minutes can save you from big agony. When I started with bitcoins transaction fee was too high for my earning, and I felt how I lose a lot on that, its better to protect your money with little losses, then to stay without all money you had.
The problem is the information, just check some youtube videos and will you see how many people are talking shit like talking to use an exchange as a wallet so newbies will do that because they are so lazy to read something concrete about it, at least people stopped to flood referral links of ponzi schemes...