As your system evolves everything is improved, even bad recordings. It can be no other way. As others have said you just need to embrace the "suck" and look for the aspects of these bad recordings that you like better in the improved system. Far worse to put together a system that makes everything sound the same. I think this is the reason so many embrace vintage equipment.
Yeah those terrible mastering technicians. Like they had the final say in how the performance was recorded. Its called appealing to the greatest number of folks and mixing for the most common playback devices. Always has to be someone to blame I guess. I tend to blame the artists more than the technicians. Yeah just do whatever you want just give me my cocaine.