>>46131238The problem was the concept in the first place.
Since they cut out Megas, they thought "What are two very popular Megas that share a type" and the obvious answer was Mega Lucario and Mega Mawile. Since they thought they should "balance" them, they made sure to switch the types in an attempt to make them "balanced", aka the more offensive one (Mega Lucario) gets the defensive stats where as the more defensive one (Mega Mawile, good defensive typing and Intimidate boost) gets the offensive stats. This is pretty much how they came up with the cover legendaries' typings. The design followed next.
But the real issue is that they're fucking idiots who don't understand typing is much more important than anything else, and by giving an amazing defensive typing to a killer offensive beast they only made things worse. It doesn't help that Fairy is actually just a good offensive typing two, realy Fairy and Fighting aren't comparable at all.
I mean it's just a theory but that's my headcanon.