because you used plate mount switches that don't have alignment pins.
I used a mixture of leftover switches from other projects. Some didn't have alignment pins, and a few ended up a little crooked after assembly. So I decided I needed to make a switchplate . I also was just looking for an excuse to get better at making keyboard things
Used swillkb's tools and then modified the file in QCAD to add the screw holes and adjust the overall size of the plate to make sure it fit inside the case. Came out great!