Discussions like this one are an outgrowth of the "social media" phenomenon. The idea these media radiate is that the universe consists exclusively of opinion and therefore all opinions are equally "real".
Fortunately, there are external, objective sources of reference which take precedence over their imaginary universes. So wake up, boys and girls!
For chess rules, the source of reference are the FIDE laws of chess to be found here: http://www.janko.at/Retros/Glossary/FideLaws2004.htm. In the latest versions the phrase "under attack" is used to define checkmate while capturing the king is explicitly disallowed. Here are the quotes that should settle the discussion:
1.2
The objective of each player is to place the opponent's king 'under attack' in such a way that the opponent has no legal move. The player who achieves this goal is said to have 'checkmated' the opponent's king and to have won the game. Leaving one's own king under attack, exposing one's own king to attack and also 'capturing' the opponent's king are not allowed. The opponent whose king has been checkmated has lost the game.
1.3
It is not allowed to capture the King
Cool puzzle, thanks for sharing!