And how many of those that swarmed to Classic left after seeing how easy MC was? Then came back for BWL, had a laugh while clearing it in 2 hours, then thought "fuck it, atleast retail gives a challenge".
Both are popular, both are good in their own ways.
No matter how you spin your words, with zero sources, I won't believe for a second that Classic is bigger than Retail. I love Classic, I play it everyday, but there is no way it's bigger than Retail.