Nothing new about this. It's been going on for some time. Are they needed? Probably not. Do they work? Yes. Can they be accurate? Yes.
We sell a lot of over weight bullets as I like to call them. Shooters want them. They have their place too, but while others may need them, I don't. Like you standard weight bullets have worked fine for me. I will admit though I don't hunt big bears, elk, moose and such with a sixgun as there's none around here. I am however around horses and cattle at times so the big bullets would work great there should the need rise.
Since I'm more of a shooter than a hunter a 44 or 45 using a 240-265 gr. bullet at 1200 fps will do anything I need done around here. In fact I could probably do it with a .357-170-K at the same speed or one of the above @ 900 fps. To each his own though. If heavy is what you want, then heavy is what you should shoot. I'm not knocking the big loads at all, I just don't shoot many of them.