I honeslty don't think they want to destroy the LBS. They are in pain and lashing out and they know you will take it becuase you love them... Its like a child screaming nasty things at their parents. They yell at their parents because they know their parents will accept it and not disown them.
They really do think you will always be there, your HISTORY together PROVES it to them.. you spend YEARS building that confidence in them that you will always be there. Subconsiously I think the whole thing is a test of your commitment and that there isn't a definite intention to leave.. Only a lot of pain and a lot of confusion...