Then recently they tried to make it better by redesigning it, and apparently gave some graphic designers free reign. This lead to a significantly worse user experience, so much so that I and many others who were still clinging on stopped using it almost entirely.
That said it had some good ideas, and the signal-to-noise ratio was much better than on Facebook. I'm guessing the active communities I visited will migrate to Facebook or similar, but it won't be quite the same.