Simply put, LD is a very linear destiny that's only ever been popular for it's epic moment.
Assuming you've already got hasteboost and damage boost, the best things left in LD are the two cleaves, they're easily twisted and outside of blitz there's nothing really left in the tree that's awesome.
Compare a centered divine crusader with 4 twists:
Sense Weakness
Lay waste
Momentum swing
A dance of flowers
With a centered Dreadnought:
Sense weakness
???
???
A dance of flowers
Momentum swing and lay waste are awesome for melee's and outshine most other tier 3/2 twists.
Now that half the power has been taken from blitz and granted to all melee all the time, sticking with the LD tree offers a lot less than it did previously.
Look at the divine crusader abilities:
- Zeal of righteous
- Castigation
- Heavenly presense
- Celestial champion
- The consecration chain
They're all great abilities that made the pre a viable alternate to LD before the shift in power.