To summarize: She's one of the least popular/played champions, and depending on whether the game's state of balance is favorable or unfavorable to her, she is either obscenely broken cancer with no counterplay or completely fuckin useless and unplayable, with no middle ground.
That's binary and what Riot does not want in the game, so why is she still around? Needs a rework fast.
Okuma3 votesShe's in a pretty decent spot in my opinion. She's a good pick in most cases, but definitely not broken.
ryona1 votesShe's in a pretty decent spot in my opinion. She's a good pick in most cases, but definitely not broken.
she's not a good pick. No CC, no damage, healing is shit.
BeatzBoyFTW2 votes52% winrate & 8.36% pickrate says otherwise.
Squishie1 votesShe is just very annoying to play vs, not broken. But honestly I'd pref she get nerfed to the ground so i don't have to play against her and get countered by w
Fashion Mage1 votes"COUNTERPLAY! CANCER! BINARY! BUZZWORDS BUZZWORDS BUZZWORDS! DELETE CHAMPION PLX"
She has a lower win rate than the other glass supports (Janna, Sona, Nami) and her play rate is only marginally lower than most of them, and Sona has the highest win rate and play rate by far, yet I don't see you complaining about any of them. Additionally, if Soraka's consistent 50% - 52% win rate is any indication, she's pretty well-balanced right now.
ryona1 votes[{quoted}](name=Fashion Mage,realm=EUW,application-id=3ErqAdtq,discussion-id=FEAyayFW,comment-id=0002,timestamp=2017-04-28T08:26:43.572+0000)
"COUNTERPLAY! CANCER! BINARY! BUZZWORDS BUZZWORDS BUZZWORDS! DELETE CHAMPION PLX"
She has a lower win rate than the other glass supports (Janna, Sona, Nami) and her play rate is only marginally lower than most of them, and Sona has the highest win rate and play rate by far, yet I don't see you complaining about any of them. Additionally, if Soraka's consistent 50% - 52% win rate is any indication, she's pretty well-balanced right now.
she's not, also winrate means nothing. no one but cucks play soraka
God Raijin1 votesIn regards to OP's post; She's actually not one of the least popular/played champs at least over the least month(according to Op.gg), she's the 41st most played champion this **month ** meaning over the ~30ish days shes been in the top 30% of most played champions.
with that out of the way, yeah, she's basically a cancer-design champion tbh, she can essentially make whoever you are fighting feel like you are fighting against a drain tank especially with the resistances windspeaker's blessing gives. Riot has addressed the issue of 
saying that his drain tanking is a potential design/balance hazard or issue. Does 
technically make champions into a drain tank? No. But she can create scenarios where the result ends up the same as though you were fighting a drain tank.
Unless you can quickly 100 to 0 a target raka can constantly keep them afloat and it is more than frusterating to play against. I'm not saying that she is blatantly overpowered, but she is one of the most frusterating champions to play against unless you are an assassin main or something.