Soraka main here.
You're doing what most people do on here, which is over embellish to try to prove their point.
Soraka is the only champion in the game that does %true damage to herself. Her heals cost HP. Yes it is significant, and no it is not "pathetic."
The problem with Soraka is that she has incredible sustain against enemies that do not have a lot of burst damage. If you don't have enough burst on your team, then you're going to have a really difficult time against Soraka. On the flip side if the enemy is taking huge chunks out your team's health bar in one or two hits, then Soraka becomes irrelevant. She isn't able to keep up with the damage.
Redemption has sort of made up for Soraka's lackluster team fighting and skirmish performance by providing a burst heal, but that item is honestly buffing every support right now and should be nerfed.
What I would like to see is a balance between sustain and burst heals. Right now every Soraka must take W first, and max it as soon as possible and rely on that one ability. Perhaps they should look into requiring Soraka to land more QW combos for example. I don't know, but I just know that the nerfs to W didn't turn out great for anyone.
While Soraka isn't in an ideal place you are over exaggerating her strength and that ultimately makes nobody want to listen to what you're saying. She's too good against comps that don't have enough burst, and not that great against comps that do have the burst. If you're going up against a fed Vayne being supported by a Soraka then you need to dispatch your burst mage to take care of them. That should be standard for any fed ADC.
There's a reason Soraka consistently preforms poorly against supports like Sona, Brand, Lux, and Zilean. They do an amazing amount of damage through their combos.
well fuck.
or 
and watch her heal for next to nothing