Yup, it's free. You open your browser and you play. You're never unwillingly charged a cent.
Competing isn't free. In real golf we take lessons, we buy new clubs. All of which cost money. Money paid to improve your scores at the real game. Huh...
You either make the choice to play & enjoy the free (& unfinished) beta game for what it is right now OR you can choose to compete for cash & prizes. You can't have your cake and eat it too.
If anyone's scamming anyone, I'm scamming WGT. I've paid a measly few dollars and have walked away with over $650 in prizes & credits in just over a year's time.
So yeah, if it's a scam, it's a really really bad one and WGT sucks at it.