Importance of mounting plate on JLF for metal case?

I was wondering what the benefits are of using the mounting plate for a JLF stick.
Im putting mine into an old dreamcast agetec so I know Im going to have to take mine off and screw the stick in like that. No questions there.
but now my friend wants to build one and is using just a metal box from his hardware store. he asked me if he needed one and then I was thinking I have no idea. Why would someone use the plate if the stick itself can be screwed in? more strength, etc?

The stick will be too long if you mount it directly to the face of a thin metal sheet.

It has been done many times before and usually it is just fine.