That was my point. And the general reduced complexity which "should" reduce the chance of something malfunctioning. In the classifieds here, you'll note quite a few "locked down" fixed powers for sale.
I have one expensive variable, a Nightforce 12-42x56. I have a Leupold 45X with a dot and a bunch of 36's, including B&L, Sightron and Weaver. The Leupold is my favorite - a real gem. I would be just as happy if the Nightforce was a fixed 42.
In my opinion, the only advantage of a variable in benchrest or F-class is to reduce the appearance of mirage. You're not really reducing the mirage, though, just the appearance of it.