Bloodborne blood gems

Why are the stats random? Randomly generated stats is why i stopped playing nioh. A story driven game shouldnt even have this mechanic. Make X amount of bloodgems similar to runes for the character. This simple system is my only huge turn off. I dont like optimizing forever, GAMBLING on dungeons to get better gems. Bad concept

Bloodborne™
https://store.playstation.com/#!/en-us/tid=CUSA00900_00