If you look at the photo in the original post then you will clearly see there are carbide scrappers on the right side.
I went to the website for the sharpener, and blew up the image to full-screen size. While it is possible that those are carbide scrappers, it is just as possible that they are ceramic. In fact, Wusthof makes, and has marketed, several different pull-through sharpeners in its time. They have one that they state is carbide. They have another that they state is ceramic.
Several of the better knife companies make pull-throughs that use ONLY ceramics, some make them with both ceramic and carbide, and some of course with only carbide. We know that non-adjustable carbide scrappers will chew up a blade, but as been said before, the typical housewife will only see that her knives are cutting better after using them. She'll use the sharpener once a month and never notice the damage, nor will she give a damn. She's only concerned with getting dinner on the table, and will be happy as a clam in her ignorance. Her knives will wear away after 5-10 years and she'll spend another $20 for a new one. Ignorance is bliss, and often economical.
WE, on the other hand, pay closer attention to what is going on at the blade level and know that carbide pull-throughs will make the blade will disappear quickly ... But....
....Take the case of John Q. KnifeCrazy... He puts his knives on a stone 2-3 times a week maintaining 'that perfect edge.' Sometimes even more often. At the end of 5-10 years, instead of a
drop-point skinner, he has a nicely tapered, very sharp
awl, and only notices the change if he happens to compare his blade with a new one. His knives will wear away after 5-10 years and he'll spend another $250 for a new one.
Sometimes pull-throughs are a good thing. Sometimes they are not. We can't make blanket statements about them and be correct.
Stitchawl