Do you think that on HIVE proposals there is no "window" for taking out profits from their "vote" investments? Without the control, and reports on what is done with funds received from proposals, there is a huge opportunity for abuse... But, let us assume there is no abuse...
Why would I finish the project tomorrow, if I can ask for more funds for the same thing for another year? The problem is in "having a skin in the game" as someone said in the comments, and responsibility for taken actions... Without that, it is hard to be motivated to do YOUR BEST...