Is it really idiocy though?
We saw a cruiser which is smaller than a Star Destroyer literally cleave in half Snokes vessel which looked to me to be at least 50x the size of of a Star Destroyer. It then continued on its path and took out god knows how many Star Destroyers on the way.
I'm not saying you could aim an X-Wing at a Star Destroyer and completely destroy it... but if you hit the right spot from the evidence presented to us in episode 8 you could quite possibly cripple it or inflict severe damage. Now imagine something equivalent to the Falcon? The Star Destroyer isn't walking away from that one.
Again running the risk of comparing real life to Star Wars... look at what a fleck of paint did to the window on the ISS, and that was travelling at a fraction of the theoritical speed of hyperspace.
http://www.dailymail.co.uk/sciencet...s-crack-ISS-window-debris-collides-craft.html
I think the whole concept was poorly thought through.