No doubt, you have already heard some people suggest otherwise. Similarly, it has often been correctly noted that local voting is one of the biggest barriers to voter turnout. The only realistic time for commuters to vote is either before or after work. They then typically face long lines as everyone goes to the polls at more or less the same time. So it's only logical that if people could vote from somewhere near their workplace, voter participation would significantly increase.
Voting systems are indeed very much like financial or reservation transaction processing systems.
All these systems need to authenticate users and then reliably and efficiently repeat and record the same set of basic transactions. And if this transaction processing is done over a network, it shouldn't matter whether one votes in one's town or from across the globe. It all sounds so familiar and sensible. But think about it. The government would have to build a system capable of processing 100 million transactions in 50 states over a 16-hour period.