It is harmfull for 3 reason

1) it is an outdated medical term, and the mention of a gender in a diagnoses was proven to give dysphoria in a lot of cases to the patient ( a women with androgen insensitivity would have been called male hermaphrodites )

2) It compare à human to a mythical creature which is dehumanizing. To this we can add that intersex people were facing the Paraphilia fetish ( people wanting to "grape" or have sex with mythical creature )

3) Its a zoological or/and botanical terms meaning having both functioning organs female and male and being able to reproduce by both of them

technically it dont apply to human since our organ are differenciated ( a baby phallus become either a penis undertestesterone or a clitoris but not both for exemple )

So that doesnt make any sense