Your observation that a customer buying at $50 doesn't 'own' the software might be true legally, but it it missing the point regarding what DRM is all about. I would consider this a valid complaint and principal matter.
Well, my first post here was about that and I don't think it's legally true at all. If a vendor sells software to me for $50 it's mine. No, not the intellectual property rights of course, but the copy of the software is mine, after all that's the item that was agreed being sold.
If some vendor denies you access to your property, wether it's by a "Accept license or shut up" or by actual DRM, you have even the right to force you access to your property. Take the DeCSS case: the entertainmaint industry tried to prosecute DeCSS author John Lech Johanssen, however, the Norwegian court ruled that John owned his DVD. Therefore, developing DeCSS to get access to the unencrypted data was considered legal, because John owned the DVD and thus the data, thus he had the right to force access to the unencrypted data which was his property.
DRM (in its traditional narrow definition of encrypting and allowing only trusted software/hardwere decrypt it) is fundamentally incompatible with the rights you have as an owner of a piece of software.
Basically the issue is as simple as: A company should have every right to protect its intellectual property but in doing so it should not prevent a customer to use his property in every way he likes. Basically Stardock understands this actually rather well, but sometimes you read some weird comments like the one you are referring to.