I am at the same point of separation as you, exOH will be collecting the last of his stuff (just trivial things, all big things etc have already gone) on Sunday.
It is heartbreaking in a way but I am trying to be positive about the amount of storage space we now have. Do you think your parents are trying to be upbeat so as not to upset you? I completely understand how their pragmatism came across as being cold so maybe give them a call and explain how you're feeling and that you feel like you need a bit of emotional support.
It is difficult for family and friends to know how to act in these situations so please don't think they're being heartless until you speak to them and explain.
I get you. Ex still has loads of stuff here and whilst I want rid of it, I know that when it is finally gone, the sadness that is tied in with the breakdown of my marriage, and the grief for what could and should have been, will surface again.
I think that when you have been treated badly by someone, parents and friends will be naturally protective and sometimes the feelings that you have about certain situations may not even occur to them.