I think it's because you're delaying the cr.B, you end up further and miss the combo. If you mash those and chain cancel them ASAP you will be close enough for it to work.
Anyway in my opinion you have a better time to end up with qcb.B, because you can't confirm the DP if the s.B hits, while with a well delayed d.B,d.B,s.B,qcf.B you end up too far for being punished by most throws, and at s.C range. You can always confirm with the orochi EX too.
Even if you deal less dmg with a raw qcf.B you keep a very strong pressure and momentum.