In this case the ships propulsion systems were semi-broken (one of the azipods wasn't working). The dry dock where it was didn't have the capabilities they need

In this case the ships propulsion systems were semi-broken (one of the azipods wasn't working). The dry dock where it was didn't have the capabilities they needed to work on it and those cruise ships have aggressive schedules so every day its sitting they're losing money. They could have towed it somewhere but thats time there and back.