Seems to me to be a vicious cycle.
I can see the problem from both sides -
I can understand a pilot who is being paid peanuts moving on to something bigger and better when the opportunity arises (why wouldn't you?)
I can also understand an operator not wishing to invest money in training people that won't stick around for the investment to pay off.
So long as there is a surplus of pilots in this country and the small demand for GA services remains, things won't change.