Kathryn Janeway

Yes, we're as shocked as she is that Starfleet put her in command

Katherine Janeway is captain of the USS Voyager.

From the evidence, she appears to love making her crew suffer.

• Exhibit one: got them stranded in the delta quadrant by destroying the Caretaker array. Apparently she has never heard of setting a timer on a bomb.
• Exhibit two: she let Neelix on board and travel with them to Earth.
• Exhibit three: upon he initial contact with the Vidiians, she allowed the organ harvesters to go free without any punishment what-so-ever, thus ensuring they would know her ship was easy prey.
• Exhibit four: she formed an alliance with the borg, even though everyone on the ship (including Neelix) told her it was a terrible idea. She didn't even bother to find out who started the conflict between the borg and S8472.

She is proof that Q is either retarded or blind as he wants her to be the mother of his new Q child.

Sometime after returning to Earth, Starfleet promoted her to admiral, demonstrating promotion in Starfleet is based on incompetence rather than ability.