reddit is useful in the way that it has so many varieties of subreddits with decent numbers of members. reddit has thousands of different communities, and it is the central hub for many of those communities. Everyone has their own likes and dislikes, and reddit can offer you a place to discuss them. You don't have to subscribe to those default subreddits if you don't want to. That's the beauty of reddit. None but a few subreddits that I am subscribed to have pictures. And most of those pictures are educational. The subreddits I'm subscribed to are generally above average people, and they know how to make a great community. Some examples: /r/programming, /r/startrek, /r/books, and /r/netsec. Those are all great communities. People generally look at the defaults and think that all of reddit is like that. However, that is simply not the case. I like Hubski; it's a great site. However, the only thing I see that Hubski could offer is an alternative to popular subreddits. That's not necessarily a bad thing, though. I joined Hubski for an alternative to subreddits like /r/AskReddit. (I'm so tired of all those pun threads.)
We have #askhubski if you like thought-provoking questions. It's pretty good and it doesn't suffer from the r/AskReddit problems of a) "I want to tell a story so I'm going to ask a question so I can tell you the story in the textblock!" or b) "I'm going to ask an extreme question most of you can't respond to, and the ones who do may just be making shit up." So far we are avoiding circlejerkish qualities. I would like to not see a pun thread here, ever. Those have been beaten to death with me - those, and novelty accounts. Please, please no novelty accounts.