I do not have the time to read regularly all the blogs to which I have established links, on my own blog. As a result, sometimes months go by without me reading them, and when I finally decide to catch up, I find out that they no longer exist, or that they have not been updated in months — and probably never will be again.
At that point I remove the link, of course.
I have just finished the above operation, and see that my link list is almost half as long now. There have apparently been many casualties among fellow bloggers, over the past twelve months. And yes, my own blogging has become more difficult and slower, over the same time frame. And I do think that the two things are related.