. . .
Too bad Time Machine doesn't create a parallel folder structure for user defined folders for user files as opposed to system files that wouldn't make any sense to try and retrieve from a PC anyway.
Since so much is linked together (apps, support stuff in /Library, and user data), I suspect that would be of pretty limited use, and be a fairly large complication.
And it's hard to expect Apple to go out of their way to help PC users any more than Microsoft helps us Apple folk.
This would also be useful for someone moving files back and forth between a work PC and home Mac (because they prefer creating visuals on the Mac, for example) and didn't want to invest in a second hard drive.
As long as you don't want to store originals there, just make a second partition on the TM drive. Format it MS-DOS (FAT) or ExFATso both the Mac and PC can read it natively.