These days, the process of buying a domain name, getting hosting and setting up a blog are totally alien to the average Internet user. Can you imagine if each Facebook or Twitter user had to do that? Services like Blogger simplified blogging and the process of posting to blogs was further simplified by Flock. We now have an age where even blogger is too complex and inaccessible for modern users. Even if such technologies were just as simple as Facebook or Twitter, between competition in the plugins added onto modern browsers and the use of mobile devices, a browser like Flock didn't stand a chance.
I used Flock for a long time. I saw a lot of promise when it was first introduced to us. I wish each developer well in the future, they have my thanks for a great tool and my admiration for such forward thinking (I'd love to pick their brain to learn what they think is the next big technology!)