A very experienced (both single and multi-crew) Citation captain once said to me "why spend a small fortune having two engines in case one fails and then try to save money by only having one pilot?"
Single crew operations in the Citation are perfectly safe but proper multi-crew operations ie with real SOPs and two qualified pilots who both know what they are doing are a lot easier, especially in an emergency situation.
Most airline pilots that I know don't hate single crew operations, they just have no experience of it on which to judge.