So if you asked those people to provide a definition of the word 'literally' that they just used, you think they wouldn't have a clue? I find that hard to believe.

But it's true that I'm not a native speaker and although on most days I use English as much or more than Dutch, that's mostly in written form, or when spoken, it's mostly with other non-native speakers, or watching scripted television/movies, neither of which I suppose are representative of how the average American actually talks.

And I may overestimate how obvious the etymology of 'literally' is to an English speaker, I guess, since it came from French/Latin like so many English words. For me the resemblance of 'literal' to 'letter' is obvious, but I guess people might not think of it - it's certainly less obvious than if English had been more consistent and borrowed both words in the same form, like in Dutch, i.e. 'letterly' instead of 'literally'.

The interesting thing about 'umbraphile' is that 'umbra' doesn't even mean 'eclipse' in Latin, it just means 'shadow', as far as I know (and as confirmed by Wiktionary, though I wouldn't claim that as the most authoritative source out there). Wiktionary also says, which seems plausible, that English 'eclipse' wasn't borrowed directly from Greek but, once again, through Latin (eclipsis) and then French - so arguably, the word 'eclipsophile' is still a Latin-Greek mixture, but then that goes for most of the Greek-based loanwords in English. As you pointed out, those generally use a Latin-ized version of the Greek word, so not 'ekleips-' but 'eclips-', not 'stadion' but 'stadium', and so on.

So it's not just about mixing two different languages, but also about a more literal etymology vs a more figurative/poetic one. And I do have to admit that I can't think offhand of any other -phile or -phobe word which doesn't just refer literally to the thing being loved or feared.

Sure, there's a difference between coining a new word that people quibble with, or misusing an existing one. But it still remains possible that in the future, the misuse has become so common that nobody calls it out or even notices it anymore.