Can someone give me an in-depth explanation why Summoner is arguably the worst DPS?

[Minorinz]

I might be misunderstanding you but... Those words are from Yoshida's mouth, every bit as valid as what he posts here.

You should know this by now that if devs don't make an official post on the forums, then you can't really bind them to a commitment. There is no official proof that this will really be happening. Also according to that post, he is "considering" it, pretty much means nothing in my books. If they really had plans then why are aren't they posting anything official if Yoshida made the call already? In other words, they don't have plans for summoner, not a buff nor an adjustment.