To be fair, the "ghoti" joke is not about pronunciation but rather about the perceived mismatch between the way a word is written and the way it is spoken.
Not exactly. Pronunciation varies between dialects and accents; it is the subject of a linguistic discipline called "phonology"; writing systems or difficulties arising from their "irregularities" with respect to spoken word do not concern it. Put differently, speech and pronunciation, while related, are not the same.
> about [...] the way a word is written [vs.] the way it is spoken.
That concept is called pronunciation.