This statement isn't fair, because most of the guest characters in The Search for Spock did nothing wrong. Let's look at the following list:
Sarek: He was extremely upset with Kirk upon entering the later's apartment, but this is understandable. Sarek was grieving for his son: he was also disappointed that Kirk had made no effort to return to Spock or his katra to Vulcan. Once Sarek realized that Kirk was not in possession of the katra, he apologized. I don't think he did anything wrong, and find his behavior completely appropriate.
Esteban: He was extremely cautious in his exploration of the Genesis planet. Whether his behavior was more the result of circumstances or his actual style of command is hard to know, as he appeared in only this film. His handling of the impending attack by Kruge's vessel was questionable, but it's important to remember that the Grissom wasn't designed for combat. It was a science vessel with minimal shields and armaments, hardly capable of standing up to a Klingon vessel.
Marrow: He was obviously a friend of Kirk's, and seemed to have a genuine sympathy for what his friend was going through. That being said, he was also "Commander Starfleet" and had an obligation to uphold Starfleet regulations. Genesis was off-limits to anyone but personnel from USS Grissom. Marrow wasn't being a jerk in not allowing Kirk to take the Enterprise on a rescue mission. He was being responsible.
David: His mistake in using proto-matter to complete the Genesis Device is obvious, but it doesn't make him a jerk. He sacrificed his life to save Saavik and Spock, something not at all different from what his father may have done under similar circumstances.
Saavik: People have complained about the implications of an adult woman having intercourse with an adolescent, but let's remember that the pon farr is fatal if it is not properly dealt with.
Styles: No question Styles was a jerk. He gloated over the Excelsior's supposed superiority to the Enterprise before the vessel had even left its docking port. He also threatened Kirk before the latter ordered the Enterprise to warp-speed.
Kruge: Oh, yeah. Kruge was huge asshole. He stole top-secret information about Genesis, took his vessel into Federation space without authorization from the Klingon High Council, destroyed USS Grissom, crippled USS Enterprise, endangered the lives of two Starfleet officers, murdered a civilian scientist, and assaulted a Starfleet flag-officer.
not cool
