Actually, this is a very sensible way of doing things. You work out what you want to shoot with your rifle, theen what bullet and cartridge will work best, and then finally you work out which rifle will do the best job with that particular bullet and cartridge. I nearly always start off with a particular bullet and work backwards. A lot of very experienced hunters do this, and nrealy all target shooters start with a bullet and build the gun around it. If i choose a rifle around the bullet i want to shoot, i have found that the rifle will always shoot it well. You just have to put the right amount of powder behind it.
And yes a short barreled 25-06 is quite possibly the stupidest thing i have ever heard of. Have a look at some ballistic tables and bullets and bullets - especially their ballistic coefficients. The 260 Rem is able to do exactly the same as the 25-06. Except that the 260 Rem can do it in a short action. Now no matter how you cut it, a short action is a better choice than a short barrel. Especially at 3000fps. A short action will be an inch shorter to begin with, but as a general rule, they are also about half a pound lighter. So you would need to cut several inches off your 25-06 to get it to match the 260 Rem in a short action. And give up a couple of hundred fps and suffer terrible muzzle blast. And completely defeat the purpose of having a 25-06 in the first place. If you want a shorter 25-06, get a ruger n.o. 1 (they are about 5" shorter than most long action bolts), or just get a 260 Rem.
Always try to cut the action before the barrel. You dont loose anything by cutting the action.
Most of the short barrel talk, as Brithunter suggests, is just marketing.