The Z-Axis exploit can be done with anything, not just Vasari starbases.
True, it just seems people complain more when the Vasari starbase is used. The quotes above where from watching a replay from a recent game and watching the two players whisper at each other. In fairness the guy who was the victim of the exploit didn't whine to us about it but he did quit when he could have stayed in the game a little longer.
I dont even know how to use it... but then I have never played online
It's not really an issue against the AI. The idea is to have the AI cheat against you not the other way around. Anyways the AI is not good about fortifying it's positions (repair, pji, hangers, etc) so it is relatively easy to take down a starbase.