Isolation booths/rooms existed when I started secondary school over 15 years ago- so I don't get why the media has only started making an issue out of them in the last few years.
I do think for some posters on this thread it would be eye opening to spend a day in a "standard" UK school. I'm currently studying for a PGCE, and in a placement school when behaviour is largely good, students are largely compliant and there are good systems for dealing with those who aren't. However, there is stuff that goes on almost daily that I think would shock some parents.
The school does have an isolation type room where students can be sent. They also have a "strike" system for equipment (among other things). If you get 3 strikes, you get a detention. If you didn't show up, this would be escalated and eventually you might end up in isolation, I suppose nominally for not having a pen. Most teachers are fairly sensible about this- if you can borrow a pen/ruler/etc without alerting the teacher to it, then you don't get a strike. This obviously minimises disruption.
I also spent some time in another school recently which is a sought after Catholic school in a large city. Behaviour, even in top sets, was really poor, persistent talking, making stupid noises, fiddling with pens (which then explode) and so on and so forth. This does (must) impact on pupils ability to learn.
I'm not a fan of overly rigid ready to learn type policies, but equally, having seen the potential alternatives, I think sometimes they can be the lesser of two evils.
And if 1 kid is persistently disrupting the other 29, sometimes it is just better not to have them in the room. Yes, you can manage it as a teacher up to a point, but part of this is often having sanctions that students want to avoid!