Sakura's ability as a medical-nin can not be overlooked, but her problem has been and always will be combat proficiency. No matter how much strength she has, it's of no use if she can't employ it. A theme that has run through the manga is, a weapon is only as good as it's wielder, Sakura possesses power but can't make use of it. Which shouldn't come as a surprise seeing as how her latent talents and potential never pertained to combat. She lacks speed, agility, field awareness-perception, and simply skill. The fight with Sasori displayed some evasive skills, but none that don't exist in even low-tier shinobi.
Getting punted by Omoi was embarrassing but oh so telling, she'll never surpass Tsunade and she shouldn't be expected to. Tsunade has direct lineage to Hashirama, Senju + Uzumaki DNA, all the while being light years more gifted. Also Tsunade fought in a real war gaining real experience, and has countless times proven to be combat savvy. I don't care if she can punch a huge crater in the field wiping out Juubi spawn, they were tantamount to children. I just don't see her ever landing an actual hit on an even mid-tier Shinobi sans assistance or putting herself in mortal jeopardy.
Sakura's worth lies in her Medical Ninjutsu specifically healing, she is a skilled Kunoichi in that right, but she remains a medical-nin who is a supplementary fighter at best. I don't know what criteria is being utilized for these rankings but in terms of shear value as a Shinobi, she is actually up there. Sakura is an invaluable asset to the Leaf's medical system and during Naruto or Sasuke or whoever's reign as the next Hokage look for her to be the head of all medical-nin. While also taking a leadership position in the village in that aspect, with the fighting subsided she can make use of her actual skills and possibly be a harbinger for some great advances in the medical field.