In my opinion it is not a gear check. But your tank has to be on the ball for first boss. Your dps have to be on the ball for second and third boss. You want people geared in case they suck a bit.

I don't think this applies to me but me as a white mage and my brother as a paladin queued up for this instance all the time. We got some super geared dps and some not so geared dps. The amount of success went up with geared players but because they were more experienced in the dungeon. If we got not so geared dps who were new and were on the ball then runs went just as smooth.

If the whole party is not geared and there is someone who continually drops the ball then yeah you are not going to succeed.