This industry lost billions of dollars in revenue due to the pandemic. It is understandable that they would want to resume operations sooner rather than later. However, there is no safe way to quarantine an infected individual on a cruise ship. Until a suitable method is developed, the leisure cruise industry is essentially doomed.
CDC warns older adults, travelers in COVID high-risk groups not to take cruises, even if they're vaccinated. The Centers for Disease Control and Prevention says the virus that causes COVID-19 can spread easily between people in close quarters on ships, and the chance of getting COVID-19 on cruise ships is "High." COVID-19 outbreaks have been reported on cruise ships in recent months, despite various testing and vaccination requirements among cruise lines. Source 3o.