It's because everyone has "magnumitis". It seems fewer and fewer people are taking the time to enjoy the standard calibers these days and everyone has to have flatter, faster, more powder and flash, more recoil, more power. That said, I was really surprised to find that I'm getting the same velocity and energy out of my .25-06 Ackley as I am out of my .257 Wby Mag, with the same bullets. But the Weatherby uses 10gr more powder, has a belted magnum case, and has alot more recoil.
I can't wait to build a .280 AI. I've always been a 7mm nut. If you knew my collection, you'd have to agree.
I do own a bunch of large magnum caliber rifles, and am certainly not new to them, so I am not hating on them. For God sakes, I just got done building a .300 Ackley Magnum, which is bigger and badder than a .300 Weatherby. I've had a 7mm STW for 12+ years. But I've always had a .308 Win in the stable. But I have recently re-discovered how nice and pleasant it is to shoot the smaller standard calibers with my .25-06 Ackley & .30-06 Ackley builds.
The .280 trumps the .270 in my book...Always has, always will. And the .280 AI trumps the regular .280 Rem. That's just my opinion.
To me, the .270 is useless when you have .284 caliber bullets so closely related in size, with higher BC's, and slightly larger diameter and heavier weights.
These are just simply my opinions, and not meant to start any pizzing matches.