I think that's a big part of it. I agree that they are not testing them long enough.
Also, I am beginning to think that they are not giving the proper instructions on how to care for the plants. I know that is true of many of the nurseries now selling own root bands of roses. If you follow their instructions, I have no doubt you will have more failures to succeed and it will takes years to have a viable plant ... in many climates.
It's clear to me that I don't have enough shade for these plants.
I am at the age where I can't just keep on experimenting and need to plant things that have passed the test of time.
Smiles,
Lyn