Ignore them. Kepp playing and having fun. Had one team moan because I was wearing Ilvl 55 HQ crafted PvP gear and they were in Ilvl 70/90 gear. Out damaged and out killed em.

But as I said, keep playing and having fun and next party says something like that, ignore em or just point out that if they want specific gear in a party, to make a premade.