The reason managers want this is because they dont know how to tell their employees are actually working so if they see the employee in the office, then they feel better. Sad but true.

This has "truthiness" but I doubt it. Engineering managers at big tech companies (which are so fond of open office spaces) tend to be former engineers.

Pointy-haired bosses who can't tell what their reports are doing are more of a hallmark of cube farms than open offices.

I think it comes down more to them not knowing exactly when the sausage is made. They can agree if the sausage is good or not when it comes out of the factory, but what happens in the middle is less clear. The thinking goes, "code gets output typically when this person sits at this desk, and so when I don't see them sitting at this desk, they probably aren't outputting code."

> you probably shouldn't hire people with ASD/AD(H)D for example

Which may be illegal to do as it's disability discrimination in many countries.

Edit: Of course sufferers are under no obligation to mention ADHD prior to hiring.

I have ADD and work in an open floor plan hell hole. Google is great for most things, but the open floor plan is killing my experience the most because of my condition. They dont really care because they have too many employees to afford switching from open floor plan now.

If you're in the US, they have to accommodate your condition. Talk to your manager and if they don't help, talk to HR. This is a lawsuit waiting to happen for them.

I can see a drop in my work quality even with music that I pick. From my past experience with offices, distracting background activity tended to make me tunnel in on one thing. This was fine for tasks which did not require complex innovative thinking.