- DREs are too complex. There are typically 50,000+ lines of code in a DRE, much of that involves user interface and audio capability, and providing the DRE interface and user experience is not worth the hit in complexity.
- DREs serve as a bottleneck on election day. DREs are expensive, and so it is unlikely that precincts will have more than they need. Since voters typically spend several minutes voting, and I've observed as a poll worker that quite a few voters take more than 10 minutes, the potential for long lines is tremendous. Once a backlog of voters is created, it only gets worse, as the effect propagates much like the airline systems gets backed up in a positive feedback loop of delays once some flights are late.
- DREs are non-transparent. The public justifiably does not trust them. They cannot be independently audited, despite the vendor's insincere claims to the contrary. Even DREs with a VVPAT cannot be properly audited because they just don't work as we would hope. Voters often do not check the paper. The paper rolls used by most vendors do not lend themselves to easy recounts, and the retrofitting of DREs with VVPAT has led to awkward and sometimes ill defined procedures, especially when a voter disputes the printout.
- Finally, a much better model for voting systems exists, namely, paper ballots with optical scan precinct counting and ballot marking machines for disability access.
So, it is no surprise that Diebold can't sell their voting business. They'd be as likely to sell 8 track players instead of ipods.