I think the suffix "ista" has taken on a wider currency (fashionista, for example) as referring in a mock derogatory way to anyone perceived as setting themselves up as some sort of opinion former or arbitrator of opinions...
I actually think the derogatory element has faded somewhat, as - seems to me these days - those described in such ways often use it, if occasionally ironically, about themselves. (Possibly an object lesson in how to take the bile out of a derogatory word.)
It is regular usage in Spanish (and possibly the other Romance languages), and a simple exoticisation of the common suffix 'ist' when adopted in English.
Barista is probably the most common example - so common in fact that its barely noticed.
I read some English grammar purist somewhere complain about an implied gender misapplication in using anything with
ista when applied to a male - because, presumably, they believed any word ending in an
a in the original language would be feminine. However, one of the interesting things about its legitimate usage – in Spanish at least – is that, whereas mixed groups are generally described in masculine terms, in this case
ista – with its feminine ending - is the standard.