Boards w/ or w/o Center Spine

So my curiosity has grown more and more as I see some new boards w/o a center spine. From what i see, and feel, soft landings are always preferred. My theory is that a center spine helps create a softer landing by breaking the water on impact instead of having a flat bottom smacking the water. So, what i was wondering was; How come some board companies are still producing "flat" bottom boards??? I know people love soft landings, and i dont think that a center spine affects buttersliding nor speed enough to notice a difference. So is it the slight change in edge to edge response or what? Cause i really feel that the only thing the a spine affects is how soft the landings are. There could be an aspect about it that i havent thought of, but im just kinda curious to see everyones opinion about this. I saw some Ronix pro models today that were flat too, so i wonder how could they possibly have soft landings if anyone thinks they do....i ride a cwb transcend which has a spine running from tip to tail and i feel it helps whether i over shoot the wake or case the wake....hopefully some of you can enlighten me from the confusion about this. So tell me; Why not have a center spine???