I have deleted all nodes and relations using query

this deleted all nodes and relations but properties persists. Searched on internet got to know that there is no way deleting properties, only think I can do is delete the database. Why while creating such important database, we considered only Nodes and Relations to be deleted. I thought developers must have thought something about it. So tell me can I delete properties, if not why? what is the thought process or its a feature coming in future?