Time travel in The Terminator

Okay so what was going on there? The whole "only organic material can pass through" story runs a bit shallow to me. I mean, do they really HAVE to go through naked?

And before any of you bleeding heart T-800 sympathizers come out with "muh time displacement equipment!" let me pose this to you: How is the time displacement equipment supposed to just know that it's all organic. Like, if you can just wear human skin (like the terminators do) then why don't people just wear stupid fur coats or something.

I don't know. I'm not a scientist. But I feel like there's a better way to figure this out that doesn't involve totally nude time travel.