This would be believable if Sasuke didn't say on at least two occasions: "I don't care what people think of me."
Yeah he doesn't care of what people THINK of him. It's just as I said. He wants to SACRIFICE himself in order to attain his goal. He doesn't want to be loved. I'm sure deep down he's afraid of his feelings. Because he's afraid to loose people dear to him once again.
About Sakura, I'm sure he didn't ever think of loving her, when she poured her heart to him back then. He was touched, because he said "thank you". But he didn't want to be loved. He had something else in mind. Sasuke has always been blinded by his goals, his will of vengeance. Maybe he could have loved her back. We don't know because he never let her enter.
Now, they have grown, and just imagine if Sasuke would be back, friend with them, maybe he could fall in love with Sakura. It's a possibility. But it's too late. Because Sakura loves Naruto more that she ever loved Sasuke, and more that she's even aware of. IMO.
I'm sure if she was able to date Sasuke right now, in a peaceful Konoha, she would think about Naruto all the time. And then she would realise with who she wants to be. Maybe Kishimoto will do it like that in the end. Because Sasuke will be back, and Sasuke will learn to accept people's feelings in a kinda way.