Advice Needed Why do people feel the need to spam?

All the time on NulledBB, at least once a day I see a spammer. I really do not understand why people feel this need to spam, as they can just contribute, or respond to other people. I understand that they are frustrated by the 15 post limitation, however that is just a minor barrier. In my case, I make at least 15 posts on NulledBB daily, depending on whether I have time or not. Also, if those people REALLY don't want to write 15 posts then they can just buy an upgrade to prime for $10 to get past it. Spamming is really bad in general and I feel that if you spam just to unlock a few posts, then you obviously deserve a ban as you are a leecher.