Monero's sole value proposition is privacy, whilst important, is such a small portion of the market. Most people will only need to use this once in a while and for particular services.
This is (unfortunately) what most people think, and for the moment, traceable coins seem to work as if they were still relatively private and fungible, although they aren't. Many people think that anonymous coins are only to buy drugs, weapons and evade taxes. Although that is of course part of it, the real deal is that with traceable coins, your bank account is on a web site visible to anyone who bothers to do some simple research.
Imagine, if bitcoin becomes generalized, that you get paid in bitcoin, and that your colleagues can see what you do with your paycheck (as they get paid by the same employer, it is not difficult to find out your paycheck from that same employer, right...). Then people will want privacy.
For the moment, bitcoin is essentially a trader's toy where nobody cares much about who owns what, except in the case of theft. Probably black markets are leaving bitcoin because they start to get aware that they leave traces for ever (if not, they will soon find out). But when people will want to use bitcoin every day, they will start to realize its huge lack of privacy when uncomfortable analysis will be done on it.
Once coins will become coloured, and you get regularly to explain at the police station where you got your money from because it is traced back to a drugs dealer caught 5 years ago, and you got some of it through a mixer when you sold some stuff on a flea market, you'll start to get the picture. When each time you try to buy something with bitcoin in a supermarket, you are taken apart to explain a few things on how you got certain coins, will start quickly to become nerve-wrecking.