Judicial History Could Be Repeating Itself
One of the reasons why so many criminal cases in Scotland are being abandoned could be that too many behaviours have been declared to be crimes.
If prosecutors are believing further action to be 'disproportionate', that is very suggestive of the situation which G. M. Trevelyan recorded in his 'English Social History' as having applied in England and Wales in the 18th and 19th Centuries. Punishments were then so absurdly heavy that juries were unwilling to convict even the obviously guilty if they thought the punishment disproportionate to the crime. It might now be the case that the criminalisation of some behaviours is now recognised to have been so absurd that they are just not being prosecuted at all.