Holster flaps.I guess that's fair. But then it's not a thumb-safety, it's a holster-safety. And I bet we can think of better ways to design a holster safety. Maybe just have the holster cover the trigger or something?
If it is indeed a holster-safety, then it was designed to try to be both a holster-safety and a thumb-safety. Instead of doing one well, it does both mediocre at best.
To be fair, I've come to really appreciate grip-safeties. I particularly like the ones which hinge at the base. I think they fill the roll of a "passive" safety (as in "just do what you do naturally") but better than Glock's trigger-dingus.
Peace favor your sword,