Most players play Moe and they attack Sexy decks all the time.

Example: (I dont really know how many who play which tyoe)
Moe 7000 players
Sexy 700 players
Babe 700 players
No-type 700 players
Total 9100 players.

If all players are active and attack 3 times per hour, we would get:
Attacks on Sexy per hour: 7000*3/700= 30 attacks per hour. (Moe attacks Sexy)
Attacks on Babe per hour: 700*3/700= 3 attacks per hour. (Sexy attacks Babe)
Attacks on Moe per hour: 700*3/7000= 0.3 attacks per hour. (Babe attaks Moe)

This is just a theory but it fit with what I can observe.

Maybe a top player with a Sexy deck that win 100% can get like 500 wins per day + 200 from players who attack to see his deck.
Still I agree it is hard to beleave.