Heh, given the way RotJ went, kamikaze runs with fighters proved to be an effective tactic. Wasn't the Stardestroyer that shivved into the 2nd Death Star crippled by the damaged X-Wing that the pilot deliberately crashed into the bridge?Given the way that TLJ went the rebels could either start doing Kamikaze runs with fighters, or just automate a straight line jump sequence on unmanned fighters (after all, you don't need to make a SUCCESSFUL jump), and blow the best warships that the FO has out of space.
"Why don't they used fighter-sized torpedoes?" has been an open question since the original trilogy.
And of course the answer to it involves the cinematic logic that governs the Star Wars universe.