I'll admit that there are plenty of recordings out there that sound like crap on a high-resolution system. But the really good recordings sound wonderful too. You have to decide where you fall in the "true to the source material" camp.
In addition to what's been mentioned above, it's important to keep your system balanced from a resolution perspective. It's possible that some of what you're hearing is new components revealing weaknesses in older components, e.g., new preamp revealing problems with a source component or new speakers revealing problems with the preamp, amp or source.
As is also mentioned above it's possible to upgrade a system without making almost everything totally unlistenable. To do this you have to first identify the characteristics about the sound of your current system that are important TO YOU. Then, when upgrading, research the prospective components to determine if they have those characteristics. If you can't listen to prospective components in your system before you buy, then this process will carry the risk of being trial and error to some extent.
In addition to what's been mentioned above, it's important to keep your system balanced from a resolution perspective. It's possible that some of what you're hearing is new components revealing weaknesses in older components, e.g., new preamp revealing problems with a source component or new speakers revealing problems with the preamp, amp or source.
As is also mentioned above it's possible to upgrade a system without making almost everything totally unlistenable. To do this you have to first identify the characteristics about the sound of your current system that are important TO YOU. Then, when upgrading, research the prospective components to determine if they have those characteristics. If you can't listen to prospective components in your system before you buy, then this process will carry the risk of being trial and error to some extent.