Because HN, reddit, et al. do not have a "real name" requirement, nor do they attempt to force you into making connections to others that you may not be willing

Because HN, reddit, et al. do not have a "real name" requirement, nor do they attempt to force you into making connections to others that you may not be willing to make. Using HN and reddit as an analogy is flawed though, because they do not have an extended family of products and services. If G+ was only G+, then great, that's one thing. However, G+ is required if you want to make an app review in the Play store, among other things. Neither reddit nor HN have anything remotely close to this.