To be fair, it's not at all clear that Buffy is supposed to be sympathetic to the audience in season 8, the way she clearly is in season 1.

I also think that it's unclear whether Buffy has been stringing anyone along--she may have been mean to Satsu, but she was pretty honest with her, and Xander rejected her pretty cold. But I guess there is definitely the sense that with Satsu, Angel, Xander, and (probably) Spike all as potential romantic partners within a short period of time the writers are making less effort to make her seem particularly monogamous.