As nice as Steam is to use, being able to download software on any computer in a fairly simplistic manner and to get reduced prices from time to time, I'm not convinced that giving up the right to own things you purchase is a fair price for that convenience.
I use Steam currently because I'm okay with that tradeoff in order to play massively discounted games.
There's no way in hell I'd buy serious productivity software on Steam though, because suddenly losing access to all of my productivity software due to some single glitch with my account on their end is just not worth it for me. YMMV, but I'm ok with Steam's DRM on games but not all software.
I've been using Steam for three years now and haven't had any account issues like that. Loss of internet connection, yes - but that's typically been an issue on my end.
It used to be I could run some Steam related software offline, as in no internet connection. I seem to have lost that ability. I do not remember when the change was made but it makes me leery about buying ANYTHING through Steam and there are some games I want that are connected to them.
If I buy a BOXED copy of a game I expect it to work without any other need other than the machine I install it on. This crap about requiring an internet connection is ridiculous. I have the discs, I even have the key still. Yet it will not run because my connection is down or worse their server is? (and yes Steam has had authentication issues)
If you want to play offline you need cached credentials, so you need to have auto-login enabled, and steam will prompt you when you don't have an internet connection (or you can explicitly restart steam into offline mode while logged in). It has worked for me very recently.
Steam has (and has had for a while) an offline mode, but it doesn't work reliably for some. If you go through the release notes for the Steam client over the past few years, you can see instances of Valve "fixing" offline mode.
You also have to be online to download, install and launch a game for the first time.
There are some games that require you to be online, but that's not universal enough to make it Steam's fault. Similarly, the notion that you have to be online to download from the Internet seems to... uh.. make sense.
That's a lot different from the DRM claim, I think.
I don't buy things on Steam, but I still use it. I'm just trying to bring awareness to terms people are agreeing to but probably know nothing about (nobody ever actually reads a ToS or subscriber agreement, ever).
As nice as Steam is to use, being able to download software on any computer in a fairly simplistic manner and to get reduced prices from time to time, I'm not convinced that giving up the right to own things you purchase is a fair price for that convenience.