I thought it was essentially Latin, so gibberish for most but possibly readable for those with a penchant for dead languages?

When used for typesetting the Latin was intentionally scrambled, so even someone familiar with Classic Latin should find it more gibberish than not. For instance the `lorem` itself was most likely a chopped part of a longer word (dolorem).

An interesting comparison of the "Modern" typesetter's lorem ipsum and the likely source text is in the Wikipedia article:

https://en.wikipedia.org/wiki/Lorem_ipsum