I'm certainly no fan of the domestic FAM program, but I actually had a twitch of sympathy for them - having management make such poor decisions without any realistic analysis to support the requirement shows the program is broken from the top down. I can offer an effective argument that NOT having a systemwide standard requiring the wearing suits or sportcoats is the correct policy - in fact, anyone who flies often enough knows that passengers who fly from certain airports or who fly certain airlines seem to have an unwritten dresscode that should be emulated by the FAMs if they want to blend in.

DL flyers in FC tend to wear polo shirts with navy blue blazers and khaki pants, as an example...so a FAM flying DL should be dressing to match. A NWA passenger flying between DTW and MSP in February is probably wearing a sweater and wool pants...so a FAM flying that route should dress to match.

Is that concept really beyond the comprehension of the FAM program managers? Have a look to see what the rest of the cabin tends to wear, gather that information into a staff advisory and require they dress to blend in.