"a few years to when Speer and Richard Lee got into a ****ing match about the Lee Factory Crimp die. "
Yep. Actually, that was in the late 70s, early 80s if I remember correctly. Fred Hundington had sold RCBS, Vernon Speer sold and CCI sold out to the Blount Group so the original owners were gone and a bunch of destructive "professional" management MBAs were running things, wrongly. Pretty much damaged Blount in the same process.
Richard Lee had just gotten into making presses, dies, etc. His tools were designed from the ground up to be made on largely automated and CNC tooling by unskilled labor forces so they could be high grade tools sold at low prices. It worked. Soon, Lee was cutting deeply into the "big boys'" markets. Speer and RCBS struck back by publishing badly misleading magazine adds showing how badly Lee's tools worked, especially the (excellent) rifle Factory Crimp Dies. (They massively over-crimped some rifle bullets and put the photos in their adds to "prove" their point.)
Federal got caught up at the same time with a big suit claiming injury from some idiot misusing Federal primers, not a part of Blount, and it cost Lee a bundle to defend against Federal pointing a finger at Lee. Lee wanted no more of that so they started posting the warnings against the use of Federal caps we still see.
I don't believe Federal primers pose any more, or at least not much more, of a hazard than any other. I really haven't been able to see how Federal caps are "softer" than others, in fact my past experiments indicated they were a tad harder, but they do use a bit more sensitive priming compound. That sensitivity does make them more prone to chain firing if one does go off in a box, tube or tray. THAT'S why they are packed in individual holes in the packages. But they also have a LOW incidence of failure to fire and I like that!
I've run a lot of Federals though my Lee auto primer tools for over two decades with no problems. But, I don't use the Tim Taylor "More Power" method of dealing with anything that doesn't feel right either. If a primer won't go easily, I stop, find out why not and fix it before continuing . So far, so good....