I worked in a department store once, A big one, nine floors.. (Eatons Centre - downtown Vancouver)
When we had to garbage stuff, security followed us to the Compactor, and made sure EVERYTHING that went into the garbage was first completely destroyed.
Things like Full sized ride-em Barbie cars, exercise equipment, and tons of stuff from my department. I know that literally Tons of clothing, went into the trash as well, and it ALL had to be slashed before it went in.
Security would stand there and make sure nothing survived - and if it wasn't destroyed enough, they made us break it some more.

True story.

Also, in cases like this video, they were probably getting credit back from the publishers. It's common practice that the items need to be destroyed for them to get back their credit. It's cheaper than shipping all back to the distributors.

I've also worked in a large book store. (Chapters/Indigo Books)
When all mass market books are removed from the shelves, we stripped the book jackets from the books (tore the covers off) and ripped the rest of the books up. we only had to send the covers back to the publishers to get our credit back on them (same with Magazines). We would destroy books by the hundreds, because it was cheaper to destroy them, and have them print more than to ship them back for re-distribution.

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