Corruption
Sorry, but evoting systems have been proven extremely insecure. Usually the companies involved in designing and producing such systems are far too open to cronyist corruption.
Back doors, lack of transparancy, no paper trail and several documentaries that have shown how easy it is to modify them to produce voting patterns that the system's corporate owners would like to see. Probably at the behest of politicians they need in place in order to maintain their government contract gravy.
The systems used in the US have been comprimised and things like thousands of 'lost' votes have never been accounted for in elections where these things are used.
Sure, pencils and paper are hardly secure and equally open to abuse by corrupt officials, but at least they don't cost hundreds of millions to put into place.
I have a huge problem paying for a system designed to cheat me out of my vote. And yes it is a shame that the people of Ireland were stiffed out of millions in taxes. But that's what government contracts are all about. If you put politicians in charge of money and you expect all of that money to spent honestly, you're a fucking idiot. They lie for a living, hardly the most trustworthy trait for the person holding your wallet.
At least Ireland isn't as backward as the US, where they allow incumbent politicians run the very elections they're participating in.