Fundamentalism has never stopped a country to achieve technological progress

Disagreed; a primary danger of fundamentalism is that it stops technological progress, and puts too much focus and attention on the past as opposed to the future. Consider al-Ghazali as the standardbearer for reactionary fundamentalist thought at the close of the Islamic Golden Age, and Ibn Rushd as the standardbearer for rationality. Consider Zheng He against the Confucian faction.

Now, that's not to say there won't be any engineers among the violent side; consider the example of the 9/11 WTC attack. I expect we will see more and more clever IEDs as time goes on.

It's also not clear to me that "rationality" is really the right thing to be worried about here. Be specific: it's much easier to talk about the impact of violent Islamic reactions to freedom of speech on the principle of freedom of speech, and about how that will alter our imperfect instantiation of it, for better or for worse.