I don't think this sounds a bad dog at-all,- I often get asked to rehome dogs that are said to be no use. One in particular was brought to me, the lad saying it won't even chase rabbits,- a few months with a mate of mine, getting fit and brought on properly, that dog was taking everything, and was perfect among stock.
Several dogs like this, have turned out to be great dogs, that i know of.
My own dog knows if there is no chance of a catch, he will not put his all into a run on it.
The drive just needs to kick in, given time.