This app was mentioned in 2 comments, with an average of 3.50 upvotes
If you lived in Japan, you would realize that not just adults play the game, but children too.
In contrast, besides hardcore fans, only children played WW. There is no alternative. You don't have to be a fan of either brand to enjoy a game, sure, but more casual gamers play TT over WW regardless of the mechanics being arguably better in WW (seriously, here, I agree with you).
Let's say 1% of players spend actual money -- excusing whether they have the means to pay. For the sake of example, let's just say that 1% of players spends $100 per month. JUST for argument's sake.
WW has 500,000 downloads.
TT has 10,000,000 downloads.
Let's go further.
PuniPuni (on which WW is based) has 1,000,000 downloads.
TT (Japanese version) has 10,000,000 downloads.
By sheer numbers alone, and given my example criteria, NHN receives $1.5 million dollars a month from WW/PP. Not bad. But NHN receives $20,000,000 a month from both TT versions.
Which makes sense financially?
Edit: PP link fixed.
I have a G2 and I actually managed to download it. https://play.google.com/store/apps/details?id=com.Level5.YWWWUS