Is there something like a "steam for VST"? Maybe it should exist, to ease the DRM pain for legitimate customers.
Nobody really cares if you use the same presets. There were countless top-10 hits with the same handful of DX7, M1, JV-1080, etc presets.
Nowadays, there are so many VSTs and they have so many presets, that nobody can keep track anyway, even if you do use their presets.
And of course you can always program your own patches on most VSTs, alter presets with layers of effects, etc...
Although there are a few larger DRM "alliances", for some reason manufacturers have not yet been able to agree on a common DRM and package management system. Currently every larger company and a number of smaller ones want to push their own plugin management system.
VSTs are a mess anyway, there are only few hosts who are able to scan all of them correctly without crashing (and these do it by separating the process that crashes from the rest of the host).