Can hospital policy strangle your future?

When I was nursing in the USA (2002-2004) I discovered some hospitals have come out with policies that will not allow them to give out references to other employers. I'm not certain the reason for this but I am well aware of the consequences such policies can have on a nurses future employability. Human resource departments will only say that
"yes, this person was employed here as a nurses between such and such dates",
but they will not make any mention of whether you demonstrated safe and competent patient care. Now, if you were an employer, would you not be a little reluctant to hire someone about whom you had no indication of their competency as a nurse?
I am back in Canada at present, trying to re-register in a province where I have worked before. In order for the registering body to give me my certificate one of the things they would like is a simple reference from a recent past employer. Unfortunately that employers' policy is to "not" give out any professional information. So the registering body says to me,
"we have a glitch, the employer will not answer the questions we need answered".
So now what?
My point here is this. If employers practice these policies, which seem to make little sense at this point, could they cause a good, safe practicing, has never had their professional license suspended nurse, lose the ability to practice nursing any more?
Forced (due to circumstances) retirement? Driven from the profession for no reason? How many is this happening to?
Are we (the nursing profession) furthering the nursing shortage through ignorance of what our policies might be doing to individuals?
Think about it.