So... my "research" on this consists of listening to the radio while driving a snowplow in the last storm (we got a foot and a half a few days ago, which is good news for a parched California, but I digress).
People they interviewed were complaining about additional fees and being essentially forced into the Etsy ad buys. So they were saying that if Etsy features your product in an ad and that ad generates a sale, they might charge you 18% or something like that. The "strike" organizer was mostly complaining about the extra fees rather than the base fee.