I get that there are and should be standards for public posts on sites like Plus. I don't have a problem with that, beyond the ones of how uneven and seemingly arbitrary the enforcement of standars is. That said, Google does provide mechanisms for private- or limited-sharing. The presumption of such a system is that, so long as everyone in those closed-circles/groups are in agreement on the "rules" of what's appropriate to share, Google really shouldn't insert themselves as the no-no police (obvious exceptions for material that is, in fact, illegal in the jurisdictions that the material is shared to).
That Google appears to want to insert themselves into semi-private communications and make determinations as to what should be allowed in those private communications is, at best, "troubling". It leaves a tremendously bad taste in ones mouth. For all its failings, FaceBook (and other social media that offer private communications options) doesn't seem to have inappropriate editorial actions as one of their problems. Frankly, logging in this morning and seeing delete actions against non-public posts where the people shared with/to have all agreed on content rules, was both a touch unsettling and rage-inducing.
I know that Google's reported active Plus-use numbers are going up. So, perhaps they feel secure in their place with Google Plus. Perhaps that feeling of security it making them feel like they have a freer hand. I dunno, but it's definitely making me reconsider my place on Plus.
So, if I drop off of Plus, it's because I have decided that Plus is no longer a suitable home for me. There's too many other options, out there, where I don't have to worry about what I say or to whom I say it.
Who knows: maybe it's less Google in this instance than it is other posters on Plus acting dickishly or simply carelessly (resharing private or even semi-private things publicly is "careless" at best). I really don't want to consider that one as betrayal of trust makes things decidedly not worth sticking around for.