Two things:
Only the earliest dungeons (the ones that drop 55-70 gear) are ilvl synced to 110. Everything else is 130.
90 gear isn't anything for threat control, especially with respect to tank weapons. You're talking about a 40 ilvl deficit, on top of the fact that any DPS with 130 gear has probably run the content often enough to do it while napping, and they just want their poetics so they can go back to Idyllshire.