Advanced Players Taking Over Beginner Lessons

I'm a beginner.  I watch various on-line lessons and lectures aimed at beginners.  I have noticed that, frequently, a poster who is clearly not a beginner will hog the posts -- instantly answering questions posed by the instructor/lecturer, immediately solving puzzles, quickly providing the correct response when multiple options are presented.

It seems that such non-beginners want to display their chess knowledge and showcase their ability to be the first and best participant in the event -- even if it is specifically aimed at beginners.

What gives?  Why do such folk decide to dominate an event where they are obviously out of everybody else's league?

I don't know. Sounds like they should't be doing that.