Just to point out that some of the information indicated could be a bit misleading now days:

-The first link is to a great post by @Zendex, who was the first to publish in-depth stats on merit distribution on the forum and its different sections. Nevertheless, the post was created in early March 2018, and does not show the current state of merit distribution on local boards.
There are more current statistics available which are updated weekly.

See for example:
Tool to run online SQL queries over Full Merit Data (Piggy)
Merit Dashboard (DdmrDdmr)

- To answer your question, the Top Merited Users do not take into consideration airdropped merit, only received merit through their posts.

- The give away thread link points to a post that was created in March 2018. Most of the links within are obsolete and are no longer running. The concept is misleading in a way, since merits are not really given away, but rather more awarded for a decent posting history in most of the cases of the give away threads.

Many people that lack merit really have no wish to create content in order to contribute to the forum, but rather get away with a quick merit and be off to posting for their signature campaign. What is more important is to have the right mindset, and maintain a contributive will there on. That requires time and effort which, unfortunately, is not amongst many posters priorities.