With the plethora of good 1-X (4,6,8) scopes available today, there really is no reason to mount iron sights on new rifles anymore, except for nostalgia. (and as noted below.) Even the levers. Unlike taliv, I do put BUIS on my AR's but that's because the main optic uses 2032's and I do not trust 2032 batteries fully. Even without them, for most ranges I'd use an AR pistol for, the tube itself is small enough to function as a big peep. It works for minute of goblin out to 50, as far as I've tested it so far.
I used to collect milsurps, Mosins mostly, and still have a few. They have stocks designed for iron sights, and indeed, the few scope sighted milsurps, and M1A's, I've fired either jarred the jaw, or had a lace-on pad. (Which only looks good on an M1C, D, or M21, or the civilian copy of the M21.)
The scope only 'trend' didn't happen overnight; Some gun writers in the 60's started making 'streamlined' hunting rifles, and with Conetrol rings and the Rosewood grip and forcaps, they had a "smart" look about them. Somewhere along the line, they discovered that the high rollover Monte Carlo they thought was necessary wasn't when they reduced the drop to little or nothing. Ideally, a rifle that is set up for a scope should have some drop, to keep the scope height above the bore axis as low as comfortably possible. The "package" bolt rifles sold enmasse these days tend to have flat combs, more like a good Trap gun, with no drop, and very high mounts. Such guns can be shot well, but they don't make it easier to do so. They tend to benefit the gun club "benchrest" hunter, the guy who shoots many rounds, often out of necessity, to zero. They make it easy to sit at a bench with the gun in a Caldwell Lead sled, or on bags, and not get a shiner or scope ring from their rifle, because their neck is straight up, like some trapshooters prefer. Nothing wrong with that, except few bring a bench to the field, and trying to hold the neck like that, particularly in the prone position for any length of time is tiresome and not conductive to accuracy. Back in my prairie dogging days, I couldn't imagine shooting prone with the Axis I have today for extended periods of time, I'd get a permanent crick in my neck!
The one type of rifle that I know must have good iron sights are African dangerous game rifles. A good solid set of iron sights are often required by PH's, they may make you take your scope off before going in the bush for the lion you wounded by taking too far a shot with that scope. Not many PH's sport scopes on their Dangerous game rifles. Savanna rifles for all the various 'boks' and gazelles? Sure. But not for The Big 5.
