Perhaps there is an aversion to the costs involved in a proper scope mount for a double rifle that creates sour grapes? Holland Style Claw Mounts and German Style Claw Mounts are $2500-$3500 for parts and labor. (optic not included)
Perhaps its misunderstood benefits? Those would be the two very traditional and truly reliable "return to zero" scope mounts for double rifles. Ultimate versatility in that you can shoot with a scope when you must and yet take the optic off the second you are looking for a wounded animal in thick jess.
Perhaps its a collector versus "modern owner" issue? From a collector/aesthetic perspective the "modern scoped" double rifle is an offensive thing to look at and will lower the value of a British double and may lower the value of a non-brit double if the person is a traditionalist. What do I mean? I mean $750 EAW pivot mounts. $350 Talley Mounts. $800 Recknagel mounts. All good mounting systems that would typically provide return to zero of MOA or 2 MOA even if haphazardly reinstalled. Technically they are not terrible options on a double rifle as they are all quality. They are ugly options when it comes to how they obstruct the sights and how they look when dressed down to create a sight channel on a classic double rifle according to the British Double sensibilities that govern the collector market for all doubles. They don't look "right" to begin with as they are modern functional mounts, not works of art. (i.e. think Blaser...not winning traditional beauty contests)
To put it another way so as to hopefully not get people hopping mad I'm calling their favorite guns and mounts ugly, let me try it this way.
Best British doubles are replicas of vintage British doubles. Everything is a synergy of form, conformation, function and fit. Every option like optical mounts MUST appear to be a natural part of the firearm with no appearance of being vestigial or an unwanted appendage. Most scope mounts are offensive to those British sensibilities in the same way as a set of bull horns from Boss Hog's Cadillac would offend if installed on the front of a ferrari. These aesthetic and collector sensibilities of the British (that you will follow if you don't want to turn an $80,000 gun into a $30,000 gun instantly) create a culture of what is "right" and "wrong" to do with a double rifle that triples down to the relatively affordable modern guns.
***Disclaimer*** These opinions are mine based on the principles of collector value and resale of fine double rifles. The opinion is not meant to disparage blazers, heyms, krieghoffs, searcys, VCs, Chapuis, merkels, and Lebeau Courallys.
Good thoughtful post. I think you are essentially correct. The English double is expected to "look" and be used in a certain way. What drives me a bit to distraction is how this essentially esthetic opinion (strongly held by many people with fairly limited experience with doubles), confuses decisions about usability - particularly for those just embarking on the purchase of a double. And as Mark notes above, there are a host of rifles, largely built on the continent, which were designed for general purpose hunting and designed from jump street to use a scope as a dismountable option. And to the German speaking owner, they look aesthetically correct. I would contend, such a rifle, has far more utility to the average hunter than an open sighted English stopping rifle.
I was in camp a few years ago, with a fellow on his first dangerous game hunt for buffalo. He had a lovely early post war Birmingham built .470. I suspect the last time he had used open sights extensively was on a BB gun in his youth. But he had been convinced that this rifle was the perfect selection for a buffalo. I arrived about mid-way in his hunt and he had already failed to get a shot at two or three bulls because he couldn't clearly see the target. He was frustrated and the poor PH was sighing a lot. On about day seven he fired early in the morning, and by dusk they had finally tracked the animal down and put him away. No dramatic charge, but based on the story, I am not sure if it was a lethal hit or the simple weight of lead, that cause the bull to quit.
That hunter, and most of us, would have been far better served with a double designed to effectively perform the client's mission - put that first bullet exactly where it needs to go when presented any reasonable opportunity. A scoped, accurate double makes that possible. An esthetically pleasing stopping rifle is, to my mind, one of the worst choices for that role. Fortunately, a lot of inter-war German and Austrian rifles are still out there (US and Canadian troops "liberated" quite a few). On most, the claw mounts are already in place, and several gunsmiths in this country can easily and fairly economically, build a set rings to fit which will hold a modern scope.
An exception to this is, of course, elephant. the client will be very close, and a stopping rifle would be very appropriate. But that is pretty much a one mission investment. I would also second the notion of the new low-profile reflex sights. They work, and we have adapted them on all our current combat rifles.