If anything, Google+ gives me some additional flexibility like audience control. For example, I could write general long form content on Google+ for mass consumption and also use it as platform for sharing content with a specific set of people (in one or more circles). Why go to (and expect) other people to follow you to each different social site for content (images, status updates, etc.) when I can compose all of them from a single place and have fine-grained control over who sees each piece of content?
Just because I can set up a personal blog site (whether hosted myself or by others) doesn't mean I want to spend the time doing so. If creating content and making it available are my top priorities, Google+ appears to be a good, centralized place to publish.
EDIT: Removed a dangling "Having".