So sometimes TV shows have "annoying Plot points" for the sake of drama that everyone makes the worst decisions. The writers in these shows rely on "Suspension of disbelief" (which humans disregard 100% objective realty for the sake of enjoying a work of fiction). Which there is quite a bit of that in this show. However - the POINT of this whole episode is that everyone BESIDES Leslie is realizing she is being selfish and self destructive. For all intent, Leslie is the "villain" of this episode, and is SUPPOSED to be like that. That is why at the end, when Anne finally gets through to Leslie, it is supposed to feel like that tiny bit of release of tension.
Then of course Leslie and Ben decide to actually get together, makes this episode worth it.
Then of course Leslie and Ben decide to actually get together, makes this episode worth it.