So...as always there's the other side of the story. I am definitely not a fanatic, but I think people have the right to know the "other side" of the story as well. :)
Confusing distros: some distributions are specifically tailored to particular tasks. However, having a larger number of possible choices should always be better. Compare it to buying a smartphone, where people usually read reviews and decide on the product they want to buy based on personal preferences.
Poor documentation: The community usually provides the help you need faster than looking through documentation. I still find it difficult to identify issues under Windows, where you only get an error number, compared to the log files in Linux.
Little support: there are lot less hostile people these days than it used to be. Identifying issues in open software takes less time than waiting for a company to release a patch for a proprietary driver or application. Also, I have yet to see _FREE_ support offered for Windows. Having people whine on forums that they "can't do this" as well as they could in Windows doesn't help either. ;)
Ways of doing things that are confusing to a Windows user: you can easily double-click a .deb file or a .rpm file and have the installer run automatically. The days of source-compiling are long gone for the common user. If said application has unresolved dependencies, the installer will look them up and offer a solution (e.g. usually installing them along). This way software developers can create smaller applications that benefit from libraries that get updated frequently (better security?).
Still too much reliance on the command line interface "sudo apt-get whateverthefuck" can alternatively be done through the package manager (i.e. Synaptic, under ubuntu). For the desktop user, the CLI is practically non-existent. There are some administration tasks that require knowledge of CLI, but that doesn't affect the desktop experience for the common user.
Conclusion: granted, Linux lacks some specialized software, but that's not the OS' fault really. Developing multiplatform software should come to the advantage of the company that creates it, allowing for increased widespread, which in turn generates revenue. Look at the mobile platform developers, most of them release software for all the major OS platforms. Anyway, I can't help but wonder why would I want to get weekly phone calls from my parents/grandparents complaining about viruses....