Making a kegerator a couple Q's

Finally found a good deal on a small chest freezer. Only 5 cf but the layout inside will fit 3 kornys plus the CO2 tank will probly fit on the ledge that houses the compressor inside as well.
My question is, why is it so common on other "how to" sites to build a "collar" around the top of the freezer so as to mount the freezer lid a few inches higher?
I've got a few inches at least head room over the kegs, factoring in the taller quick-connects for the beer and air lines, stil should be fine, albiet close.
Im jazzed about finally haveing my HBs on tap soon and not bottling so much.

One of the reasons is that it does no damage to the freezer itself. That way, if you ever get a different setup, you can remove the collar and the freezer can be just a freezer again- with no holes in it.

Another thing is it adds more room for a carboy. Carboys are taller than cornys (with the airlock attatched anyway) and this way you can ferment in one part of the freezer and have cornys on tap in another.