It's just that so many people read "you're my dark place" positively. This line came directly after the issue which could not have disrespected Spike or Spuffy more (unless it was written by Willingham). Everything Buffy said from "beneath you" to "convenient" to equating dying with "studly" showed no respect whatsoever. Having her categorize him as her 'dark place' reinforces that whatever she might feel for him, whatever affection or lust, she still considers him as being the lesser. That's not a foundation for a relationship. It's a damn shame that no matter what he does, it never puts him anywhere close to an even playing field.