Why would you ever take morde bot?

I don't see the reason for it, sure the dragon buff is nice, but adcs still are superior. They are ranged, they have sustained damage, most have a form of mobility or cc, everything morde doesn't. Along with that Morde's ghost got nerfed so even if he does manage to get a kill on the ADC it wont be as useful as it would before. I don't think putting him into a duo lane is what is going to fix him or is the right path to take with this rework.