A "design persona" is a stereotype that designers use to justify their decision to discriminate against some subset of users. It seems innocent at first, but it inevitably devolves into the developers crudely binning individual users who submit but reports of feature requests into those stereotypes and then, very often, disregarding their feedback without thoughtful consideration.
"Our Personas document says this software isn't for engineers who taught themselves to use Linux in highschool. This guy who submitted a request to add tabs to the interface looks like a nerd, we don't need to take his suggestion seriously even though he's suggesting a normal thing people who fit into other personas would also find useful."
"Our Personas document says this software isn't for engineers who taught themselves to use Linux in highschool. This guy who submitted a request to add tabs to the interface looks like a nerd, we don't need to take his suggestion seriously even though he's suggesting a normal thing people who fit into other personas would also find useful."