Not everyone can clone. Some people don't own Emerald, and some people don't know the glitch even exists.
And we're not trying to get rid of cloning, either (Since only ones who can really do anything about that are the people who design the games).
I fail to see how cloning makes the game more challenging in any way whatsoever. It does the complete opposite, as you have access to an infinite amount of Pokemon to use for trading purposes (Which makes getting everything you ever desired extremely easy, when it shouldn't be), as well as access to an infinite amount of all the items.
I find it more challenging because you have to come up with good strategies to beat other peoples really good teams, which have become good from cloning to get the stuff they need.
I am happy that you guys aren't cloning because cloning can be really addictive, but it ruins the spirit of the game, so im gonna try and stop it too.