Kendell, I would imagine that using a root name as a base and playing with it to arrive at a variant is done for the same reason that people "mess with" a good song-in other words, for the creativity of it all, and to put their own "stamp" on it.

Another way of saying this is to make the name their own just as jazz & blues and gospel singers & musicians [if not folk singers and musicians] make a song/music their own.

{Of course, there's some people who think that a song must always be played exactly the same way every time. Not me.