I'm going to go ahead and say, while I am not someone who believes there is anything wrong with steam, the consolation to your first point is rather weak Destruction is Fun!
If Valve were to go out of business and suddenly the service would fail, the question isn't: Why wouldn't they release the patch, because it wont cost them anything. I think the real question would be: Why would they release the patch, they are out of business, it's no longer anyone's problem. Them being a modern corporation, the interests of the company do not mirror the interests of the individuals.
This is a rather callous way of looking at it, but non-the-less applicable.
That said, the arguement for weak internet connections is one that has always bothered me. You can get a stable internet connection at McDonalds. Everyone has issues with their ISP, but often this doesn't mean a once a week thing, where your out of internet for days at a time. I have an issue myself about once a year, that is solved in under a day. I get an issue about once a yearly quarter, where the issue is solved in under an hour (Often because of maintenance on the part of my ISP.) I don't live in a big city, infact I live in a town of under 1000 people that often has issues with natural forces effecting the power/communication lines in this area. Yet, still the issues with my ISP aren't numerous.
The nearby town of 100k people, regularly have issues with Comcast, which is one of the big providers for that town. Most of the people I have talked to, have similar issues to me (In terms of how long it takes to solve the problem) occurring with about twice as much frequency.
I know people who live in far more remote areas who have stable connections with Comcast as an ISP though, so the problem in the nearby town seems more of an issue with their grid, not as much an issue with the service as a whole.
It just isn't that difficult to get yourself a connection, it is a difficult justification to swallow.
Now, there were issues with the Offline mode until recently... but it's just that, there were issues until Recently. By my understanding, it has been fixed now. So, as is said above: You only need your internet for activation purposes, after that run it offline and you'll be fine. If your posting up here to complain about Steam... you obviously have that capability.