Regarding a couple of statements from this article.
People have a variety of reasons but most of them pick Linux hosting because it is open source.
No.
Another reason why customers opt for Linux is that it allows them to employ other technologies that are open source as well.
No.
The vast majority use Linux as a server OS and technologies such as PHP, HTML5, Javascript and various other scripting languages when building websites because they are free to use and there are a variety of resources available to learn and leverage these technologies. Of course there are open source advocates that support these technologies in part because they are open source. But these users are a minority overall. Open source users who actually change the source code for these open source projects for their own purposes also exist, but are an even smaller contingent overall. Open source advocates would like to believe that anyone using open source software is a rabid advocate of open source as a philosophy, but the truth is much more pragmatic. Good, free tools attract users regardless of the philosophy behind them.
Note, the linked article is an even handed explanation of Linux vs. Windows hosting and I don't think the author intended the quoted statements above to indicate a slanted view toward open source advocacy. But the quotes are representative of a false cause and effect relationship - if popular software is open source, it doesn't follow that it is popular because it is open source.