What's the point of unfollowing those who do not follow back?

I get asked often as to why I made JustUnfollow, why should anyone unfollow if they aren't followed back. There are a lot of "legitimate" reasons why you would want to unfollow someone who isn't following you back on twitter and I'll list some of them here, keep adding more as and when I remember new points and you can pitch in your thoughts as well!

1. Many a times, users with the intention of increasing their follower count tend to follow you. You being the "good guy" follow them back and start seeing their updates. Now, this person who happened to follow you, stops following you thus making others think that he/she is someone worth following since the number of followers they have is much more than the number of friends. Shouldn't you unfollow such people!

2. When I first joined twitter, I did not know what to do with it. And, twitter isn't an easy thing for new users, they do not know where to start. So like any newcomer, I ended up following a lot of unknown people on twitter. Slowly I made friends with a few of them but never interacted with many others. Most of the times, I realized I did not interact much with those who did not follow me. The reason's simple, you would strike a conversation with me only if you see my updates, for which you need to follow me! It was time to clean up, I had to unfollow those who did not follow back.

3. Twitter has a follow limit. You cannot follow more than 2000 users to start with. Now, when you reach that limit, and want to follow a new user, you would need to unfollow someone from those 2000 friends. Whom do you choose to unfollow? How do you make that decision? To make things easy, you can start unfollowing those who aren't following you since they really do not care about your updates!

Do you have any legitimate and valid reason to unfollow non-followers?

Apart from non-followers, I'm trying to figure out more reasons to unfollow users. A few new features might be added to JustUnfollow soon. Stay tuned!