It's like they implemented it without have any idea why the customer would use it... They were just copying other people... Badly.
And while we're on the topic of sharing, why doesn't Google Reader send shared items to G+ yet? It has sent it to Buzz for quite a long time, and Buzz isn't even popular.
The link shows up on your Google profile, in the "+1" section. It's would be fairly convenient way of sharing bookmarks, if anyone used Google profiles.
I would much rather that it integrate with G+, or at least allow selection of which groups I want to be able to see a single item rather than just being able to decide who gets the entire stream, but I find it very difficult to believe that you required "several software engineers" to set it up.
Of course, it's very fashionable to hate Reader, as it has been for a while.
If you were designing a search algorithm it does not seem like you want want to give much weight to an embedded easy approval button (reddit, digg, +1, like, etc.) compared to something that requires more investment of someone's time and thought, like making a del.icio.us bookmark. I mean, half the time you have to go try to remember what your password was, then have them send you a password reset mail, then re-login -- now that's a bookmark I care about.