The reason is very simple, study, will, and knowledge.
However,
If your post like this is very thin what you expect, merit.

https://bitcointalk.org/index.php?action=profile;u=1014729;sa=showPosts;start=720

https://bitcointalk.org/index.php?action=profile;u=1014729;sa=showPosts;start=620

Only you get a few tokens and make money, it doesn't generate merit.

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However, if your post like this your dream will come true, merit.

https://bitcointalk.org/index.php?topic=5206035.0

You can get everything in the Bitcointalk Forum as long as you want to give the best for the members here.
Maybe try to fore the best post, you will definitely get Merit.
Note:
Merit is not moderated by Legendary or lower ranking, it's free to give and receive for quality reasons and useful posts.