I'm just saying there's a middle way between lighting up the map like a Christmas tree and no wards at all. Trying to ward at key locations and playing around those. Vision is boss, don't get me wrong.
Naturally I do ping. Guess it has the same effect as warding - if someone doesn't pay any attention, no attention is paid xD
To put it in perspective, the high elo support generally spend 75% or more of their money on vision (this includes oracles and pink wards). You'll see them finish the game with 1, maybe 2 items and a boots. Shurelias, maybe a mana item, possibly locket now that it's cheaper. The core build is boots, sightstone,and a GP10 (kage's, philo). Everything else is fluff.
It's because vision is so important. More important than the extra stats you would get personally from an item. Aura items are a little better as it's for the team but again, vision more important.
Even if your team makes some mistakes and doesn't spot that 5 man gank coming, I guarantee they will die even faster if the map is nothing but fog of war. If the game is anywhere in reach, vision will turn the tides.
It is frustrating as a support not being able to build items. That's something riot tried to fix with season 3 by increasing the global gold and adding a couple more support oriented items but really it just allowed supports to spend more money on vision lol. They're promising to address it again for Season 4 but I'm not holding my breath. Support is about CC and vision. That's it. The ones that spend all their money on items or build AP or something silly usually lose the game for their team.
http://www.probuilds.net/champions/Sona
There's maybe 1 or 2 games in that entire list where they have more than 2 complete items besides the core. Most barely have 1. It sucks but that's the best way to play support.