Interesting, I did not realize square drive was uncommon in the UK. It's a really nice screw head to work with, and as someone mentioned elsewhere in the thread, becoming more common in certain woodworking applications in the US.

It's a Canadian invention, and to this day quite localized to Canada, where it's nearly the standard for carpentry (at least, every deck screw I've ever seen here is Robertson drive). It's good that it's catching on, it has a few distinct advantages over Phillips, my favourite being that you can mount a screw on the driver and it will stay on the driver due to an interference fit, freeing your other hand to secure, support, or stabilize.