Mmmmmm.
For me, I dont see this as singleminded as much as obsessiveness. But that due to her other portrayals outside her own book.
If you look at the pattern of incidents in the Justice League storylines with Graves, the Trinity War, and then post Forever Evil, we see a woman who is shown to be on the edge of excessive violence on numerous occasions as she tries to rectify problems.
Basically, every time things start to go badly for someone Diana cares about, she veers into dangerously violent territory.
Now the JL where she cuts on Green Lantern could be seen as once off with her love interest Steve Trevor in mortal danger. Though still pretty extreme, considering her actions put civilians in dangers [says Batman]
But then Superman gets into the same jam and she basically throttles Hephaeustus for information, even though he's about the only God on Olympus who has never given her cause to attack him and is a pretty decent sort of guy.
Then most recently she threatens Luthor with decapitation, and has Barry Allen scolding her about how criminals deserve justice, not a sword to the throat. And even goes so far as to imply her standards in this regard are at best antiquated [or at worst barbaric].
Now its its not like we haven's seen Diana get angry before. Gail Simone had her really tear into the Society when Etta Candy was kidnapped and tortured by Genocide. Diana even, lacking the lasso, resorted to roughing up Cheetah. This never sat well with me, by the way, and I said so to Gail on the forums.
But the difference is at least in those cases we had access to Diana's inner voice, explaining her feelings to us. In the three examples I just listed all we have are an outsiders view of a woman with her emotions barely under control, if at all.
And you have to ask yourself, is this character as written really who you want around. Because lets face it, superheroes have to face these sort of threats a LOT. And the way she is written OUTSIDE of her own book, it looks like Wonder Woman's volatile temperament is ill suited to heroing.