I did say that rhyming was not necessary, I also said that rhythm could change. You can do anything you want as long as it works. You may want a very disjointed rhythm in your lyrics if your song is very disjointed.
My main problem with the lyrics he posted was not that they didn't conform to some rule but that the way he was putting them down is very obviously not controlled.
Plus it should be said that there are lyrics that are meant just to fill space and complement the music (most lyrics it would seem) and then there are really great lyrics that work well with the music and express something very interesting.
