That's how you know it's not about the technology; it's all about getting rich quick. Once that has been taken away they lost interest in developing TON.
I think it's safe to say that without fungible tokens (Grams), the blockchain itself (TON) isn't very interesting (despite what they want you to believe).
Furthermore, it only banned the sale of said tokens to americans and in USA - if TON is so great and certainly profitable, I'm sure there are lots of wealthy Saudi or Chinese investors that would be glad to invest. It's just that the "greater fool" theory of investment fails if everyone knows that they won't be able to unload these securities to unsophisticated mass market in USA.