Nice troll. Actually, it's kind of a lame troll. I suppose, as is normal on /., you didn't read the report from Prof Halderman.
The initial problem was a string interpolation vulnerability in a modified Ruby library that executes a shell command to encrypt PDF ballots. That's a pretty basic mistake that has nothing really to do with Ruby or Rails. If you interpolate into a string (or concatenate data into a string) without sanitizing the data, and then execute it, you're asking for trouble, no matter whether it's Rails or Java or C. This is also pretty basic security stuff, and there are tons of guidelines and tutorials in the Rails community for avoiding this kind of mistake. There are also plenty of code vulnerability scanners that would pick this up. It's amazing that the DC team didn't use one of these to check their code.
But they had plenty of other problems such as easy-to-guess passwords and a lousy IDS configuration.
So the real problem was with the people who developed and implemented the system, not with the tools. I've seen plenty of similar mistakes in systems developed using all sorts of technologies. The developers clearly didn't have a very solid background in security. That's OK actually, as long as you have someone on the project who does and who can check their designs and implementation. Sounds like they didn't have anyone well versed in security, which seems a bit odd for an e-voting project. I'm certainly no expert on security, but I am RoR coder, and even I know not to make these mistakes.
But I suppose it's fun to bash the Rails programmers because they are in really high demand and able to command very high billing rates :-) I'll take the bashing along with the money and the ease of programming!