In my own experience, most people who view it this way don't consider scaling. While pen and paper is an easier attack for a single voting station, it is far more difficult to scale. Every voting place brought in on the scheme has more people who could be caught or decide to go public, and that is assuming you are able to get in contact with those people in time to ensure they are able to intercept the voting. With voting machines, one good exploit, especially for wifi enabled machines, can easily infect larger numbers.

As to why other countries don't have people viewing it this same way... I don't think it is because they have better ability to consider scaling attempts to exploit a system.

http://blogs.mprnews.org/newscut/2008/12/timewasters_the_bal...

In the case of the Florida Presidential vote, they ran into the problem of "hanging chads" where parts of the page that were intended to be fully punched-out so a machine could detect the vote were still attached to the page, leading to further scrutiny over deciphering the true intent of the voter's ballot.