Itemization isn't really a problem as a support. The problem is more that you're expected to build certain items, and if you don't you're either trolling or don't know how to build.
A support specific item like the jungle knives might make the role more appealing to some, but there are easier fixes.
First off, dis-assign lane roles. The idea that you need a ranged champ and support bot Lane is not nearly as important as team comp. If the last several weeks haven't pointed that out hard to everyone with AP carries and support mages, I don't know what will.
A marksman mid has worked just fine in the past, and if you were to put Zed or Kat or Talon bot with a support (especially an aggressive one like Syndra or Annie), how fast would a team win? It just requires your team being on the same page.
Secondly, it takes a certain mentality to really play support. An attitude of 'the team comes first' versus 'i suck I haven't gotten any kills and I've died 5 times'. Supports job is not to get kills, it's to set up your partner/team for kills.
Thirdly, get everyone else educated about the support role. The entire last paragraph applies in reverse to teammates of supports. Know that their role is to set you up or save your backside, not to nuke the other team. Yes, there are some champs who can occasionally scale that way, but they're few and far between, and largely depend on the skill levels of everyone in the game.
Fourth, grading system needs an overhaul. It's next to impossible for a support to get an S these days, mostly because when you play the role properly, it's not worth an S unless you never die. I've had games in support go 3/6/36 and gotten an A, when I'd call that a damned good support score. This is the major reason why supports won't die for their team and it needs to be fixed.
There's more but I'm out of time to type.