This thread is so old, but so entertaining.
Too big or too deep. I want the bag to hold my stuff, but I also want to be able to find my stuff, so no black holes. I tend to prefer E/W bags for this reason.
No shoulder straps. Crossbody is better, but it has to have a strap.
No zipper. I don't mind a flap over the zipper too much, like Longchamp.
Fussy closures. I want to be able to get in and feel around for what I need and close it back again if the bag is on my shoulder. I don't want to have to try to get the two pieces lined up just right to close it.
Flap bags. The flap is just in the way and annoying. A magnetic closure helps some, but arg.
Doesn't open wide. The thing I hate about my LV Pallas BB is the ring that the strap attaches to goes through both sides of the bag - so you can't open the bag any wider than the ring. I hate that.
Heavy even when empty. I will not buy a bag that's heavy empty. I sold a
Coach tote for this reason and I stay away from many D&B leathers for this reason.