Chat is much more personal and intimate than a shared newsfeed or email. Automatically making chat contacts out of hundreds of strangers or people I will only ever exchange one email with is inappropriate and bad UX.
They don't need to know when I'm online. They don't need the ability to interrupt what I'm doing. I don't need my chat list huge and unusable. By all means give me the ability to add people and circles to chat, but making it automatic seems silly.
I guess the problem is that you added a bunch of strangers to Google+. That's not what Google+ is for.
I've kept my Google+ account limited to just friends and family, and I've found it amazingly helpful for them to be added to chat. I used to use irssi+bitlbee, but now I find it easier to just open Google+ and find people to talk to.
Ultimately, I think your Google+ experience is going to be a product of your expectations. I've talked to my family members that aren't computer programmers, and they like all the defaults for Google+. You might not, for the same reason that I run my own mail server -- we're weird, and we're the 0.00001% that doesn't matter to anyone trying to make a product for hundreds of millions of users. (It's why we read HN instead of Reddit or Slashdot: mostly to be different.)
(Another problem might be apathy. Internally at Google, our software is so integrated that it would make Apple cry. Unfortunately, it's all geeky stuff that 99.999% of the world doesn't even know exists. Because we have it so good, we might not even consider the fact that our users aren't as lucky.)
> I guess the problem is that you added a bunch of strangers to Google+. That's not what Google+ is for.
Google+ is a social network. As such, I have a hard time imagining that it can be successful by forcing users to use it in a specific way. If the people using the service want to leverage the service in a certain way, there doesn't seem to be anything "wrong" with that. In fact, I'd argue that Google should take such usage as feedback into improving the service to better incorporate the new usage patterns.
EDIT: This perhaps should go as it's own comment, but I'm going to throw it here for the time being:
People like to use social networks as a public publishing platform as well as a way to share with friends. This is to some extent supported by Google, as they have encouraged people to use G+ as a blogging platform. The behavior we see with the HN circle is (I'd argue) just people attempting to hack functionality onto public side of G+, which IMHO is a part of G+ that is sorely lacking.
I guess the problem is that you added a bunch of strangers to Google+. That's not what Google+ is for.
Um... Isn't that the reason "circles" in Google+ exist? To draw lines?
It's why we read HN instead of Reddit or Slashdot: mostly to be different.
I don't think anyone only "reads" one community. According to interest, one participates in many?
Personally, I found all this quite confusing (and just when I figured how to "circle"; doh, limit has been reached for adding people. But, you can start adding tomorrow!)... and following the advice of sp332 and betterth, I avoided falling into blunders like Google adding all 1000+ contacts to my Gtalk or notifying each and everything that ever happens in G+ universe.
Moreover, since now people are split inside circles, am I supposed to update the circle manually everyday?
Agreed, what should be a simple thing has turned into a usability nightmare. Why is Google limited the number of people I can add? Why is there a hard cap of 5000 profiles that I can add total?
If this is supposed to be a social network, why are these limitations in place?
They don't need to know when I'm online. They don't need the ability to interrupt what I'm doing. I don't need my chat list huge and unusable. By all means give me the ability to add people and circles to chat, but making it automatic seems silly.