There are actually very few people today who have used a Linux based desktop. There are though lots of things being said about Linux. If you have heard stuff about Linux, beware of some misconceptions. Given that the development of software like Linux evolves at a very fast pace, sometimes these misconceptions are the fruit of an old (outdated) experience. Sometimes it's just a lack of experience all together. So let's go through some of these myths:
-Linux is only for experts.
Wrong. There are distributions made for the average user as well. In fact, there are distributions for almost anything you can think of. Some distributions are made for musicians, some specialised in design, some... for computer experts too!
-You need to know how to use a command line to use Linux.
Wrong. This was the case in the past but is no longer true. Although you can still use the command line in all GNU/Linux distributions, you don't have to if you don't want. Most things that are done with a command line can also be done now through a friendly graphical interface.
-Linux is free so it can't be high quality.
Super wrong. First of all, not all distributions of Linux are free (!). There are companies making millions selling distributions, software or services related to GNU/Linux. Second, there are many more people involved in the development and testing of GNU/Linux than on any other platform, in fact, anyone can review and improve it. Watch this TED talk about institutions vs. collaboration to understand how collaborative work and institutional work are different.
-None of the software I use can be installed on Linux so I cannot make any use of it.
There are plenty of alternative software to be installed in Linux, usually for free and of high quality.
-I have tried Linux and didn't like it.
Some people are not aware that there is not just one Linux but hundreds of different distributions based on Linux. Some will certainly please better than others. It's like food. Some flavours will please better than others but one cannot say not to like food because of one taste that was not agreeable. I recommend new comers to try one of the mainstream distributions listed here.
-Linux has too many bugs.
No more than any other operating system (I won't cite any names). I recommend reading the article "Is Ubuntu GNU/Linux ready for the masses?" for more insights on the average user approach to Ubuntu.
-I develop proprietary software because with Free Software I would loose my job.
Wrong. There are many more job opportunities when a software has it's source code open. In fact, when a software is closed (or proprietary) only developers of the company who owns the software can work on it. When a software is distributed with it's source code, any developer can work on it. Read this article about how FOSS developers earn their money.
-Linux is less secure because its source code is revealed so attackers can read how the system is built and find security holes.
The so called “security through obscurity” (the security achieved by hiding) is a weak defensive strategy. Security in GNU/Linux systems is improved exactly because the source code is revised by many people and repaired quickly by anyone who has the skills to do it. There are also architectural differences between UNIX-like systems and Windows based systems that make Mac and Linux computers more secure. Read the article about why Mac and Linux don't have viruses.
There are certainly many other myths and/or realities out there. Use the comments to share them!