So, I don't blame anyone since most people come from the post Microsoft era, where almost all the computing lies that they had grown up with stemmed from Redmond. This is a graph, that will either help clear things up, or make it even more confusing. It is a graph of various popular Linux distros since the Linux epoch 16 years ago.
Most people would have heard of RedHat and SuSE, which are two of the most successful commercial distros today. RedHat is arguably the most successful commercial Linux vendor, while SuSE is second and owned by Novell, which has been battling Redmond before getting into bed with them quite recently.
Debian is famous for being the most 'vanilla' distro out there. That's why you can see that there are a lot of other distros that have grown out of it and are still based on their Debian roots. The most famous of it's offspring is Ubuntu, which anyone who has been keeping up with the technology industry would know of. They're based on the Isle of Man, just off the English coast.
So, if I were to describe Linux as an ice cream, a distro would be all the different flavours available. Different people have different tastes and requirements. So, it's quite impossible to provide a single ice cream flavour to cater to them all. So, that's why there are so many flavours of Linux. Each flavour caters to a different market segment.
However, this is probably why Linux is quite daunting to most consumers. They don't know how to choose when presented with choice. Well, just like my gelato experience in Italy, the only way to know is to try it out. Pick any flavour, and try it. Some, you will immediately hate the moment you try it. Some, you will grow to dislike after having it for a few days. While one, you will fall in love with for the rest of your life.
Hopefully, this graph will help people select a distro. Pick one. However, don't pick one at random. Then, you will end up with random experiences. The best thing to do is to check out some reviews and ask a Linux user friend. I'm sure that you can find one. There are so many of us out there. If you don't like it, pick one that is from a different branch of the tree, so that you get to try something fairly different. Then, if you've narrowed down specific features that you like or dislike, pick one of it's cousins. And then, hopefully, you will fall in love.
I started with Slackware in 1996, had a disastrous fling with Debian and Mandrake, rebounded on RedHat for a year, before returning to the loving embrace of Slackware for life. I swear by Slackware, which is arguably the oldest surviving commercial distro around. There aren't many quite like it in this world, as evidenced from the graph.