A small blade safe can hold hundreds of blades and it’s like 4"x3"x3". Makes sense they thought the inside of drywall 5’x3’x1’ would be fine. It can probably hold tens of thousands. Even with a new blade daily that’s decades. And when you tear down the wall you’re dealing with Sheetrock, nails and screws already. All that time would have dulled the incredibly thin blades.
This is all to say: it seems wild but was a decent idea.
We used to have a Victorian era house with one of these. We had to replace that wall in the bathroom and there was this huge pile of rusty razor blades in the wall. Had to use tongs to pick them up for disposal.
Not just hotels but houses too. There would be a slot inside the medicine cabinet for disposing razors into the wall. Dude who came up with the idea was probably like, “we’ll all be dead from nuclear bombs before any of these fill up or needs to be renovated”.
Dude who came up with the blades in the wall thing was also clairvoyant. He was just mostly wrong in his clairvoyance, a few details would prove to be true.