The reason I prefer a safety that locks the bolt on a hunting rifle is this: One less thing to have go wrong, or worry about going wrong before a shot at game. It is one thing to lose a shot at a deer because your bolt was not fully closed, it is entirely another matter if your rifle misfires because of a partially open bolt when something mean and nasty is headed your way. I have a friend who had misfires on two bucks over the years because his bolt handle was not completely closed. I have a strong opinion on this, a bolt rifle I use for any kind of serious hunting WILL have a bolt that locks shut. It is not only Remington that had this feature, the early Ruger 77 tang safety models locked the bolt, later ones did not. Of course, the 77MKII locks the bolt in the third position. Tikka still has a two position safety that locks the bolt when safe. It is the way it should be. It was deleted by some makers because of folks who failed to follow one or more safety rules while unloading their firearms. A real shame in my opinion.
Another reason to have a locking bolt. I was on a horseback elk hunt in Montana years ago before I swapped in the locking safety on my 700. The bolt would not lock shut, and the retention feature of the leather scabbard relied on a flap that closed around the bolt handle. The whole hunt, I was worried about losing my rifle, because the bolt would open and pull through the flap, and rifle would not be secured.