I don't think very many people actually like Pocket. I wish it would die. It makes Firefox look like it's no better than any commercial browser -- not even Chrome installs that kind of stuff in my toolbar by default!
Pocket is easy to dislike before you start using it -- it's just UI bloat, as you point out.
But the feedback from people who do use it is overwhelmingly positive. A lot of people love Pocket. It's enormously popular, despite the impression you would get if you exclusively went by HN comments.
Personally, I've just recently started to try using it. It hasn't really captured my enthusiasm yet, despite addressing one of my larger pain points with a browser. I still think I'd prefer management capabilities that felt more built into the standard (well, Tree-Style Tabs) tabs/history experience. But it's early days, I'll have to see how my Pocket experiment goes.
They're certainly good at surfacing appealing-looking content that isn't vapid when I try reading it. That's worth something.
