Wild charge is not "they pick without a doubt". If you play with Discipline Priest or Shadow Priest he can give you Shield in right time and Displacer Beast become very strong defensive cd. Dots won't break your prowl also aoe won't knock you out of prowl if you have shield.
Also if you use Displacer Beast enemy players lose you on focus bar.
Wild charge in human form is only 25 yards which is not a lot in my opinion but again to gain max benefit from Displacer Beast you need to team up with Priest : )