I mean, It's not just encourage more variation. I think the damage will probably be pretty good anyway, but,
you have to remember that doing J236D>j214D in CP gets you 3000 damage in two moves (two proration hits). and 46D>236D gets you about 2500 in 2. And at high prorations. In a sense there's a bit less freedom.
Here are some numbers. (p2s excluding starting 6c)
6c>J236D>J214D>2944 .84 P2 Real P2 .41
6c>46D>236D> 2612 .932 P2 Real P2 .456
6c>214D>22d(charged)> 2479 .8178 P2 Real P2 .4
6c>236D>214D> 2437 .7743 P2 Real P2 .379
for fun
6c> CT > 2010 1.00 P2 Real P2 1.00
6c>Blades> 3126 .721P2 Real P2 .5047
You really want to fit the special effects in. It's hard to say how much it matters that you can't use one if you started with J214D.. It's nice to have both options available though.
When it comes to combo theory, theoretically the 'time limit' on combos might mean that doing damage faster might make stuff better than it would otherwise seem. When it comes down to it I think that is part of why they changed the J236D> J214D effect. One to make it less time and two to make it so it could be killed by SMP (Since SMP actually has no proration involved anymore, it seems, if we could link our SMP moves we'd end up with combos like that Hazama 10k OD combo...)