There are 25 million people using steam and a comparative handful of people suffering a few minutes or hours delay once or twice in their entire lives.
Putting aside the nebulous definition of 'active accounts', how do you know there's only a handful of people suffering problems, or that their problems are minor? Not everyone has an account on the Steam forums, not everyone that has an account posts, and it's a wasted effort to post when there are already dozens of people posting about the same issue you have and the general consensus is that there's nothing you can do. Even if you had access to data about what Steam Customer Support regularly deals with, that only covers the people that have invested the effort in requesting support.
There are a lot of people who have had problems with Steam, who simply haven't said anything because they would rather be doing something like playing their games. Post the question on any forum with a large and widespread user base and you'll see a lot of people who have had issues.
From my sample size of counter strike players, very few have problems with steam, and those that do can almost always solve it thru valve's support protocols.
I don't understand how this is supposed to be significant. What is the sample size? How did they participate, e.g. using a poll or survey? Did you take steps to prevent sampling bias?
Even assuming that all the players who are currently playing Counter-Strike are having no issues, the number tells us nothing about how many people who want to play Counter-Strike are having issues, or how many people that have had issues managed to solve them with the aid of Customer Support.
For the record steam released a major overhaul of their client a few weeks ago. I think it updated while I was playing my game. At some point I got a message saying I needed to restart the steam client to get the update, which I did at a time of my choosing. Then I played my game again.
The Steam client does not update itself while it is running; it only checks to see if updates are available and prompts for a restart if so. Steam will always check for updates when it is being launched in online mode (even with no active internet, according to my tests), and then install them.
Assuming that the update does not introduce more problems, there's nothing wrong with this method. Since updates can and have introduced problems in the past however, the inability to prevent client updates except through perpetual offline mode or disconnecting your internet every time you plan to launch Steam may be troublesome.