I guess many of us noticed it during their game: the AI sure loves to build freighters, and send them everywhere. And we sure love to build isolated small-quick-ships to hunt them down and destroy them. (Sometime, we don't even bother to build small-quick-ships, we simply used outdated ones).
However, if the AI would put some weapons on these freighters, we would certainly have problems. Since they removed First-Strike rule, a freighter would have the opportunity to fire at least once on it's attacking vessel. And I sure know that after some time, my "freighter-hunt" would be somewhat... in trouble. I would either have to put serious battleships on the task (and off the line), of accept to loose my outdated ships.
Which would be a good AI's strategy, compared to the actual's behavior to send sitting ducks everywhere in the galaxy, so that everyone can take a free shot at them.