So... Your complaints boil down to "a lot of games use Steam"? And WHY is that a bad thing? Also, your use of the term 'monopoly' is not particularly solid - it tends to be thrown around a lot at anything that happens to be really big, but Steam is not even trying to be a monopoly, there's nothing stopping other services from trying to be big, but the big difference between them and Steam, is features.
A lot of games use Steam, as do a lot of people, because it's a great service. That's it. Nothing else can remotely compare. In a single client, you have an in-client store (including wonderful deals that you'll rarely find elsewhere, even in retail), a single convenient game library that can also include non-Steam games, automatic updating, cloud saves, chatting, friend and group lists, and other community features, Steam Workshop lets you check out new content for certain games that other people have made (levels, mods, etc), and Greenlight makes it easier for Indies to get into the service, now that the community can give their say. Its offline mode is a tad stuffy, but that's a relatively minor issue.
Honestly, the only reason I can think of for anyone to really hate it is if they loathe any kind of DRM on principle, despite the fact that Steam is pretty much the only form of 'DRM' out there that actually provides a good deal of benefit and value to the consumer.