This site is a great resource and I hope Brendan keeps posting amazing content.
He's spreading and making available knowledge about perf, ftrace, eBPF that would otherwise remain relegated in Linux kernel development circles. He's also contributing to bcc (a tool in the eBPF ecosystem), but his main merit in my opinion is marketing, with his books and blog (I'm using the term in positive sense).
Windows is much more popular and has many more apps, but I can come up with a handful of reasons why I don't like it or think it is objectively worse.