Have used a lot of FC and no problems. The idea it's soft goes back about 20 years to a ONE time run that was. Not it's one of the hardest out there. Getting loose primers seems to me to be "heavy" handed powder oriented. I've heard the same thing about Rem. brass, and had people not want to buy if, so think there's a lot of bias in peoples minds, that may not be exactly true.
No it was NOT a one time issue that goes back 20 years. Guys are having the same problems with brass made last month. Experience that produces a common result is not bias.