I was talking to Freeze about this, and he said I should make a thread on it to see the forums' views and opinions on this.
We're a community that tends to go off-topic quite a bit, there's no doubt about that. But the admins are also constantly pressing for us to... stop. Because staying on-topic is better for organization. It's cleaner. But personally, I don't really fully understand or agree with how adamant they are.
If it's a thread in Serious Discussion or something with a very specific topic, like a specific movie or whatever, then yeah, I can fully understand why tangents that go too far are unacceptable. But if it's just a casual thread in Stuff about, I dunno, your day at school, or something that happened in your life, then what is the problem with tangents? Why not just roll with it if that's where the conversation leads? Tangents usually develop on casual, broad topics, anyway.
I suppose it would be disrespectful to the author of the thread to suddenly go completely off-topic, but like I said, threads like those are casual, anyway. They're not meant for a serious debate. And it's more often gradual than a sudden change in topic.
Clear-cut, perfectly-organized, always-on-topic forums are boring, to put it simply.

If a conversation gradually shifts, it's because the community wants it. If that's what we want to talk about, why shouldn't we discuss it?
The argument against it is that one should just make a new thread. But it's much harder to spark conversation that way. It's not quite the same, either. The only way I can think of describing this is using a bad analogy. It's like making a tangent joke to a friend in class that's sparked by something the teacher said, only to be told to raise your hand if you have something to say. Chances are, you're just not going to say anything then.
Tangents are enjoyable. They bring activity and spark conversation. It's not like they're entirely spam, either. They usually have some sort of topic to them. If not, they're purely for enjoyment and amusement.
Amusement is good. We want amusement. Members return to forums on which they have a good time.
Anyway, what I'm saying is, particularly on boards like Stuff, I really don't understand what's wrong with going off-topic. I mean, I suppose you could split any topic that goes on a tangent, but that's annoying as hell and I'm sure you don't want that.
Um. So yeah. Discuss. Tangents: positive or negative?
Should we be a nazi forum? Give me relevance or give me death?