Am I missing something here? Why is Alistar having his E nerfed even further?

I'm honestly just confused. Call me bronze scrublord, what have you. I don't watch the LCS or glue my eyes to winrates, so forgive my ignorance, but I've got some serious curiosity over these E nerfs.

Riot already went through and nerfed it once, now we're doing it again, but reducing the already (from what I've seen from all my time playing Ali) minor heal down even more. Why? Is it game breaking in the LCS or something to have this minor heal when Bard or Soraka could do it better? Are the new masteries responsible?

Yeah, I know he's a tank with a heal, but it's an abysmal heal if you ask me. Essentially all these nerfs are saying to me is to not even touch your E unless you want to activate your passive. At this point, I'm wondering if the E should just be replaced by something else. I never found it useful for healing that much, maybe as a small "Here, now give me a free assist," but that's about it.

Someone please enlighten me.