My mother sailed on the “Johan Van Oldenbarnevelt” in the 50´s. Emigrants to Canada/Australia and repatriating Dutch from the East Indies.

The ship was sold to a Greek shipping company and was then used for cruises in the Med and to the Canary Islands.
However, one day fire broke out.

The investigation
The Greek Merchant Marine Ministry launched a two-year investigation into the Lakonia disaster. The board of inquiry maintained that the Lakonia never should have passed safety inspections before sailing. Lifeboat davits were rusted and lockers containing lifesaving equipment failed to open. The drain holes in many lifeboats were without stoppers, so that passengers had to constantly bail water.
While a lifeboat drill had been conducted by the crew a week before the fateful voyage, only five of the boats had been lowered in the drill. All of the boats should have been tested, the board argued.
The board of inquiry issued a number of other charges. The order to abandon ship was given too late. Operations on deck were not supervised by responsible officers. The crew, despite a few cases of self-sacrifice, failed to rescue sleeping passengers from their cabins below decks.
Eight of the Lakonia’s officers were charged with negligence. Captain Zarbis, his first officer and the ship’s security officer were charged with gross negligence. The other five men were charged with simple negligence.
Source
But to come to your question “Anyone get the impression that most cruise ship captains are just guys who look good in the uniform?”
Yes.