The picture below shows the Dip Trace switch pattern on the left. Clarifying it just a bit, the center picture is what this pattern is showing (my apologies for flipping it 180). What the symbol shows is that pins 1 and 2 (or 3 & 4 if flipped 180) get shorted together when the button is pressed. But this accomplishes nothing, because pins 1 and 2 are internally connected together inside the switch. If you believe the symbol, you think 1 and 2 will be connected when the button is pressed, but in fact, they are always connected, and if you wire the switch this way, it will always read as pressed.
The right hand symbol actually shows what's going on clearly. 1 & 2 are connected together inside the switch. 3 & 4 are connected together inside the switch. When the button is pressed, 1 & 2 are connected to 3 & 4. Glance at the symbol, and everything is revealed.
I have made the mistake of laying out a board with incorrect switch connections. With a little effort, you can sort of fix the mistake by rotating the switch 90 degrees and bending the pins to fit but it's a mess in the end. It's so much better when the symbol is clear and concise so it's hard to make a mistake!
I don't think there's anything further to add here.
BTW, Mrdeb's switch, copied from what he calls a schematic, is only connected to one point in the circuit, so for that switch, it's not going to work anyway.