It seems like the author thinks Skype helps terrorism by allowing terrorists to communicate securely. This is true, it probably does. But by that logic, Wikipedia aids terrorism by letting terrorists get encyclopedia articles for free. We shouldn't let the "terrorism" boogeyman take our right to privacy away. There is plenty of reason for ordinary people to want secure VoIP. Maybe you don't want your boss listening in on conversations with your family. Maybe you don't want a casual eavesdropper to listen in on your conversation and take something the wrong way.
Anyway, if Skype sells out to the governments of the world, it's trivial for the terrorists to use something else. I could probably write an encrypted VoIP app in an evening. So if you want to eliminate secure communication to aid the fight on terrorism, you are just giving up your own rights. You won't have secure phone calls, but you can bet the terrotists will.