Why would anyone ever design a website in inDesign?!

A designer would do that.

Designer here: I know I shouldn't do it and I understand your pain. But for me, it's the fastest way to get mockups. Because I'm used to inDesign for print jobs. But if I would hand you something over, I would use sketch. So that everybody is happy :D

@heyheni my teacher taught me to do it in photoshop