I wonder when Riot will understand, SUPPORT ISN'T A BACK UP MID
I don't think I can be more clear about this.

ARE NOT SUPPORT ITEMS

ARE SUPPORT ITEMS
I don't think I can be more clear about this.

ARE NOT SUPPORT ITEMS

ARE SUPPORT ITEMS
I am curious why you feel this way. "All your spells now slow" seems a very supportive item to me, as does "Mark a target; magic damage dealers on your team deal more damage to them."
Do you think the ITEM purchase or the PURPOSE of the item purchase within a champion's play pattern should define whether it is appropriate for a given champion in a given role?
I would agree that Void Staff does not feel like a support item to me, but is purchased primarily because it is absurdly undercosted late game when MR values are high and because supports tend to have low offensive scaling with non-penetration stats.
Actually abyssal scepter could work as a support item. The auras wont stack over the entire team, but if two people have it then they get the double aura. so their spells benefit from it.
I might be wrong though.
The only two non-support items there are Rabadons and Void Staff. Abyssal, DFG, and Rylai's all benefit the team. And on many supports that scale with AP, AP increases the support's utility (Lulu, Janna, Soraka, or Morgana). But on some supports, such as Annie or Morgana, it helps to build AP because part of what those supports bring to the table is significant damage and AP ratios
Rylai's has been core or near core on Soraka for ages. It's always been good on her, she just couldn't afford it until this season.
Also, 3 of those support items are crap and one of them isn't that great compared to it's alternative. No support in his right mind would get them.
This has nothing to do with riot, but the players themselves, lol...
In my opinion the problem lies on why getting a pure utility if you can have utility and damage or utility and tankyness. Champions that can only offer utility aren't being picked as much as the ones that also do other stuff, even when their utility is way lower.
On a side note, change Nami Tidecaller's Blessing to something like "Connects with target allied champion, adding X magic damage to his auto attacks while costing you Y mana. Gives half the move speed from passive at each attack. Casting again or moving Z teemos away breaks the connection."