This article on Linux Journal, called "The Many Paths to a Solution", really gave an idea to explain to people who don't know much about Linux why are the so many distros out there.
Many seem to believe that the main reason that there are so many reason for there being more than 50 actively maintained distros, is that Linux must not be really that good. That's not really the case, since the users of most of those distros could easily make a point for why their distro is great for them.
Each distro represents a path to a solution to a problem that a group of users have to solve. That's why not every distro is a fit for every user, and also why many become disenchanted with Linux. In many of those cases, the user wasn't matched to the right distro to begin with. While in other times, the expectations weren't meet to what the distro offered.
That's why its vital to match new users to the distro that better suits their needs, not to the distro that we like best or we currently use.
There is no distro that will fit every user out there, while distros like Ubuntu and Linux Mint will be a great fit for most users, there are some others that would need something else. For example, big companies needs are better meet by Red Hat Enterprise Linux or CentOS. There is even a distro focused on science laboratories called Scientific Linux.
As such, before recommending a distro its vital to know that the user need and expects from it. Otherwise you can be doomed to fail to give the best solution to that user's needs.
It's time to take a better way to match user to the distro they need. Only that way Linux, and FLOSS in general, can have the level of usage and good will they deserve.