Yeah but, for Joe User, there are no alternatives.
He wants to use Outlook, because everyone he knows uses Outlook. He wants to use Office, because everyone is talking about Word and Excel. He wants to play some games, because they're all the rage these days.
He doesn't know about Linux and, if he did, he couldn't go about installing it himself. If he did install Linux, he would have to learn a different mail program. He would have to install LibreOffice, and that's not Word. And he couldn't play many of the games that "everyone else" is playing anyway.
Now that Borkzilla is laser-focused on The Cloud (TM), and has finally started porting parts of its software empire to be Linux-compatible, we have a chance to see the day when Office will run natively on Linux and DirectX maybe as well.
That will be the day that will signal the start of Linux on the Desktop, because there will be a real alternative, ironically brought about by the same entity that has done its level best to keep Linux out of the desktop.