100% speculation and it's the markets fault in the start, not the vendors but I am beginning to question if vendors are super happy with all the FE orders after evo. Most vendors started with escrow and are used to it/built the business they run on the idea they need to use escrow but now with the new markets and multisig it seems hardly anyone is using multisig other then newer vendors.
Maybe it's a flaw in multisig as I haven't checked it out admittedly but if vendors starting off can take it I know some of these bigger operations could deal with it. Basically I think we are to blame for FEing too much and not giving the vendors any real incentive to learn and add multisig escrow to there listings, vendors are probably by now enjoying and used to the amount of FE sales and I'm worried DNMs as a whole won't recover even as we add new things like multisig to prevent scamming markets.
TL;DR: Vendors who didn't use to require FE are doing so now and probably enjoying that security for them, we as buyers aren't demanding enough to get safer options for escrow like multisig (which as I admitted am guilty of myself) and am worried this will turn into something irreversible or at least highly negative for a long time to come.
I believe multisig transactions require more overhead than traditional escrow for vendors. Add in the fact that vendors don't receive any benefit from escrow and you have the current situation where many vendors are requiring FE.