I too love plain text data, but absent a universally accepted standard, meta data is needed to avoid guessing a document's charset, encoding, and line ending convention.

Associating such meta data with text files wasn't simple in the beginning, but that changed in the 1990s. Nearly all filesystems since then allow meta data: POSIX compliant filesystems support extended attributes, mostly used for security meta data. Even ancient HFS (Apple Mac) supports meta data. NTFS supports it with alternative file streams.

While possible, no system I know of attempts to use any such meta data, probably due to a lack of standards. A pity.