It is not that much of a problem, since 95% of the people probably use one of the top-5 distributions. If we go by Distrowatch's popularity, those are Ubuntu, Mint, Fedora, Debian, and openSUSE. Two those are derived directly or indirectly from Debian (Ubuntu and Mint). So, three of the five are virtually the same, except that Ubuntu and Mint are more focused on user-friendliness.

The more serious problem is the immense amount of resources that are wasted on developing multiple desktops, photo editors, photo managers, music players, chat clients, etc.

Some people will say that competition is good, but if you have that tiny market share, I think it would be better to focus on the overall experience.