Why should some medals be public, or available to the public? They are awarded to a private individual for acts which will often (particularly the ones involving gallantry) have left a last impact on the recipient.
To my mind the only person entitled to say what they want to happen to the medals is the recipient, and then its down to the family to do as they wish with them. If a VC is held in a boxroom and seen only by family then so be it - it is their relative and their wishes that matter, not anyone else. Let the family do as they wish, and if they don't want others to see them then so be it.
What matters is the citations, the stories and the history that must not be forgotten - not the medals themselves.