Hipster INFJs are like the opposite of mature. They are some of the most self-congratulatory pretentious douchebags on the planet. They're like the emo version of the INTJ who thinks he's always right and the rest of the world consists of mere plebeians.
If INFJ is the measuring stick for "maturity" then Fi in any form, unless it's mimicking Fe, will always be perceived as "immature." How gauche.