Lifestealer in higher level play?

I haven't seen, well, any games that I can think of, where Lifestealer was picked up in a competitive scene. Why is this? Also prove me wrong please and show me a game where he's picked up. Why isn't he picked up more? He (from what i've seen) ; scales great into the late game with his % dmg and lifesteal, has essentially a free BKB, and a good ganking spell. He also has very good CC with his slow. Just curious because he is definitely one of my favorite heroes and I think he's fun to play. (Especially with his ulti hehe)

EDIT: On a side note, i've played many games where people have said that Midas on Prophet / Naix is a bad item choice because it delays other items and doesn't really give too much bonus. Is it a bad item in general to build, even if it's before the 9~ minute mark and you use it for the EXP bonus and not just for the gold?