The reason a developer wouldn't return a deposit is because the money has already been spent.It would have been logical to just add it to that thread . But then again people would read that deposit monies have been tied up for at least 4 years on this project. Also they would hve read how many similar promises have been made in the past.
This does not speak well for the ethics or financial strength of the developer. There are no excuses that can cover that "inconvenient truth."
I would NEVER risk one dime with a developer who did not give my $$$ back EVEN if he had a compelling legal reason not to do so. No solid developer should need deposit $$$ to spend on current financial obligations.