Yes, she isn't the only one who cares for him. Juubei and Emishi are still there (although Fudou and Kagami have buggered off by that point). However, I'd note that by then, Juubei has reconciled with Kazuki, and Emishi with Shido, and this has changed their opinion. Yes, she isn't the only one he cares for - but I do think he cares more for her than Juubei or Emishi; remeber when he claimed he was setting Juubei up to fight Kazuki as a test of loyalty? Would he have asked Sakura to do that? And several times he does ask Sakura - and only Sakura - if he's doing the right thing.

There's no evidence that their love goes beyond the fraternal, but neither is there evidence that it doesn't, and in this series there are maybe two pairings that do visibly go that far. It's all extrapolation anyway. I chose to extrapolate in the direction I found most psychologically satisfying and rich in story ideas.