Is it possible they ask the employees what food they wished to be served on that day? And the ones who are complaining were a minority who didn’t want it?
It’s equally possible that they didn’t consult employees and just didn’t something that they thought was appropriate.
It’s not clear how it happened.
Corned beef seems to have originated in Ireland and Scotland, but was commonly used throughout the British Empire for the past 400 years. I assume the cooking and salting process makes it last much longer without going bad, which would make sense for long voyages.