I ve got alot of experience in home care, dementia care, nursing care and residential care.
Nursing homes have to have a nurse on the premises at all times. The have better beds like the beds that sit you up, raise in height etc etc. They deal with PEG feeding which is were someone is fed through a tube in their stomach.
Years ago if someone had bad pressure sores, were in bed all day, had uncontrollable diabetes, needed feeding etc then they were go into a nursing home. However its not the case anymore.
Nursing homes can be around £200-£300 a week more expensive per resident than residential homes/care homes.
The government and local authority dont like paying nursing fees unless absolutely necessary so they tend to keep people who really are nursing care in residential homes. This is were the problems begin as people need specialist nursing care and instead of having nurses to do it, they have having carers doing it.
From what you describe about your father he sounds boderline nursing however i can imagine the local authority saying hes not severe enough to be transferred to nursing.
In residential homes a district nurse visits daily to change people dressings etc where as in a nursing home the nurses deal with all that.