I think we're jumping the gun here if we assume Google is going to count all users as active users, especially since they haven't actually done this yet.
In fact they have, several times. They also count active users vaguely as any user that has used any Google's services, even the search engine, as long as he or she has a Google+ account. Misleading as hell.
I just went through the Google registration process. The whole article is a lie, of course; as you would expect from any Microsoft associated publication; your Google+ account is only activated later on by explicitly signing up. Unfortunately even I, who have done Google registration quite a few times, didn't realise that until after I had signed up for Google+ with my new account. I have verified that even if you make the same mistake as I did you can trivially delete your Google+ features from your Google account.
So in fact, it's not a lie.
I hope your torches and pitchforks aren't nearby, because Google — the Company That Claims It Does No Evil — is doing something that might make you want to reach for 'em. Apparently the search engine giant is now forcing new Google account users to join Google+ and Gmail.
Until now, creating a Google account was quite simple. You could either use an existing email address or create a Gmail account.
The newly redesigned sign-up process for Google accounts now includes fields which ask for your name, gender (required, thanks to Google+) and mobile phone number (optional). Once you've got those fields filled out, you're led to a page which asks you to create your Google profile — better known as your Google+ account.
There is no option to skip this step and avoid the creation of a Google+ account (and a Gmail account), which is something you might want to do if you're interested in using only some other Google services.
"A complex system that works is invariably found to have evolved from a simple system that worked." -- John Gall, _Systemantics_