AEM creates additional version of a media assets when you revert between different versions of the asset. This is functionality as design, as the system:
In case this behavior is not desired, you have following options:
Use this option if you don't need the version creation only, but do need other metadata writeback features
With this option the metadata writeback is turned off, use this option in case none of the features of writeback are required
[1]:
[2]: