There's a reason I used the word "Beginner" here. This isn't talking to the newcomer to the site, this is the newcomer to the hobby.
Dear Beginner,
Welcome to the wonderful world of AC, and the aquarium hobby.
The wording here was chosen so as to point directly towards the target audience. It clearly does not point to the newcomer to the site who has years of experience.
Beginning hobbyists do come here looking to learn. Yes, 99% of the members do know more than 99% of beginner hobbyists. It is nothing short of arrogant for a beginner in the hobby to act like they know better than someone who has been in it for 20 years.