No. It is definitely not just anti-gun rhetoric. A certain percentage of Remington 721s, 700s and Model 7s will definitely accidentally discharge when the safety is switched from safe to fire. This most often happens when the rifle has been cocked (by cycling the bolt), the safety placed on, the trigger pulled relatively hard while the safety is on, and then the safety switched off. Though nobody would intentionally do this, it is a common occurence during hunting and range sessions. It also appears more common if the trigger mechanism is somewhat dirty, or there is ice in the system from a light rain plus freezing rain while hunting.
There has been lots and lots of litigation as result of accidental discharge and death from this design defect. The failure of the system has been proven in several lawsuits. It is also my understanding that the original designer of the trigger system has testified that he warned Remington of this defect while manufacturing was underway, and urged them to fix the problem, by installing an additional small part, which would have cost abouty 50 cents per rifle, but Remington refused.
On a personal level, in my 45 years of deer hunting with many different types and brands of rifle, I have never witnessed or experienced an accidental discharge, EXCEPT for one accidental discharge of a Rem 700 in 7 mag, one of a Rem 700 .243, and one of a Rem Model 7 in .243, each and every one of them under the conditions I have described. One occured by my father in law, one by my brother, and one by my ex-wife, all very experienced deer hunters and shooters. Nobody was hurt in any of the instances, but it was so unnerving that we all swore off these particular rifles in original factory condition. NEVER had this happen with any other brand of rifle.
Now, very experienced rifleman and hunters may say that it is the fault of the shooter, because he should scrupulously clean and maintain the trigger system, and take care that no water or ice ever gets down in them. That may be true in a perfect world, but the truth of the matter is that the world isn't perfect.
Happily, there is a very simple fix. Just buy and install a Timney trigger in the rifle. I understand this solves the problem. Talk to your gunsmith for more advice.
Best, Mannyrock