Thai Marriage

Many Thai marriages aren't on paper and any farang setting foot is a status raiser for the family (and regardless of what she says, they WILL expect money to be sent and money will get "lost"; I hear too many stories of families bilking farang for as much as possible). Farang failure to send money is also a reason for divorce so regardless of what's said, the husband is supposed to send her mom money all the time.

So does that mean that most Thai marriages are not really marriages? Its just for show?

No, it is due to money usually. And in some older cases because they just 'did not have time'.