I'm not saying that it shouldn't, I'm just familiar with how government works. Government may seem like one organization to an outsider, but it is not. It is largely a giant bureaucratic monster made up of fiefdoms of offices that serve specific functions and are generally oblivious to what other offices do or how any of it fits together.
The way people vote is either specifically defined in state law or delegated to individual Supervisors of Elections (or whatever they are called in a particular state). As busy as these Supervisors are right now, this close to the election, the chances of their making voluntary changes to the system are pretty much non-existent, though they may be convinced to change after the election. For them, cost is probably the primary issue, and the ones who have moved to electronic vote counting probably don't have funds to hire enough people to do counts by hand. They would have to get these funds from the state or federal government. If the machines are in use due to a state law, it may take years to change; you would have to either go through the courts or vote in lawmakers who want to change the law, then wait for them to get the bill considered and passed, then signed by the Governor, who can veto it (the process may vary slightly in some states). If you go the court route, there are usually appeals that can take years and a whole lot of tax dollars to come to a decision on, and there is still no guarantee that we would win.
I'm not saying we shouldn't push for it, but it will take a whole lot of time, money and effort to accomplish. It won't happen before this election.