Why is Dataquest using SQL Style Guide by Simon Holywell instead of some other style guide?

Screen Link: https://app.dataquest.io/m/577/coding-with-style/6/rivers

Here at Dataquest we generally follow this SQL Style Guide.

Why is Dataquest using SQL Style Guide by Simon Holywell instead of using any other style guide like:

Is there any specific reason?

No, there are no reasons other than our content team liked it. If I add my personal opinion, I think SQL Style Guide by Simon Holywell stands out because it is not only well written, but it is neatly presented compared to other style guides. That said, when it comes to styling code, the most important thing is consistency. You can choose any style guide you like, but you should not mix things up to ensure that your SQL styles are consistent.