Maybe because Philips are designed to cam out and destroy the screw socket,bainin wrote:i use them occasionally for cabinet type stuff. My router table build from a few months back used them. They are fast and positionally agnostic...can place them just about anywhere so long as they provide the support you need.
The issues I have with them are :
1) Sometimes the screw doesn't set correctly to align with the pre-drilled hole. Then when you drive the screw in-the clearances are small enough that you can get the screw point popping thru your second piece. Keep a file handy
Its hard to tell visually if you have the screw placed properly in the pre-drilled hole to avoid this.
2) I'm sure there are valid reasons for forcing me to keep the special screw head adapter for my drill - but I'm constantly worried I will lose it. Not sure I see a good reason why these screws couldn't simply use a Philips head.
b
The Robertson (square) head is superior in many ways, it is immediately apparent if you have the correct size bit, (with Philips I'm never sure), the screw will stay on the bit without it being magnetic,
Here in Canada everyone uses them.