People join the NS to go to sea. The only problem with long deployments from the crew point of view was the pay did not match the personal sarcrifices the crews were making. Had they been deployed on any other overseas mission, they would have been paid for the difficulties caused by long periods away from home and family.
Doing away with the hope of long deployments, in my opinion would be even more detrimental to morale.
It would also make the case for the EPV/MRV more difficult to justify.