Why don't more ADCs build Black Cleaver?

Except for who occasionally build it,why don't more ADCs build this item,i remember Ruler played with and it was a meta build for some time before i believe BC got reduced damage but increased hp,i tried this build just now and got 11/2,it doesn't feel bad at all.

Now im not saying all adcs should or could rush Botrk BC,but buying it somewhere down the line even as 5th or 6th item seems reasonable,im guessing it could also stack good with PTA + the Armor shred means your team mates will down the target faster, maybe making up for the damage lost if not going .

It seems weird that its a decent pick on cause of her ult applying it to multiple targets pretty fast,but its overlooked on who can basically do the same or building it on but no even thought she could basically stack it instantly with Q auto E and can use the CDR

Any thoughts?