Because DE shaving, other than a couple of hundred hobbyists on the Internet, isn't even a thing.
It's insignificant.
Here's the thing, when cartridges were introduced, did men give them a try and think "nope, that's not for me, give me my trusty DE razor and blades, and soap and brush any day"?
Did they buggery. They dropped them as soon as they could due to one reason, convenience and that's the reason almost all men wouldn't thank you for a DE razor.
Men have always just had other stuff and things to be getting on with without having to waste any more time and effort twatting about in the bathroom.
Just saying, like.