You're claiming to be busting myths, but somehow it's "obvious" that all new players on Korthos are F2P? And only run Normal? Pure myth that all are F2P, and even for those that are, you think they never join LFMs for non-Normal difficulties put up by other players? More myth.
I have no idea or opinion about whether new players are quitting due to Champions, but your myth-busting is busted.