Sometimes, we do something thinking that it's a wonderful idea. You know, like when you look at a stray cat and think to yourself that it looks sweet enough and that petting it won't hurt in any way. Instant regret. Well, these cats are experiencing the exact same thing, not having the bestest of all days.
Window blinds may be fun to look at, sleep next to, and periodically check if they're good nail sharpeners, but they are definitely not meant to be used as a toy for climbing. That is not a good decision, you little hooligan, but you know what? Sometimes you have to learn that the hard way, just like all of these cats did.