Agreed. And sometimes, advising a topic starter to close the thread since he/she receive a sufficient response in regards to his/her questions often result in bashing from other users. Oftentimes, a thread is bombarded with redundant replies only with different words so as to hide the similarities between them. That's plainly annoying to read.
This is one of the issues that I have as well, however I find that there seems to be inconsistency when it comes to the moderation on these boards. As pointed out above, some topics are locked when the topic becomes irrelevant or the topic has been answered. But others languish on these boards even after the pleading of posters to lock the thread! I've seen multiple threads on the same topic without any moderator stepping in to remove duplicate topics. Consistency seems to be an issue with me. JMHO
I don't remember a time where someone made a delete request or I saw a spam thread that didn't get removed after my report. It was probably reported by others as well. If I hadn't reported it I wouldn't notice otherwise. It also depends on the board that you're discussing a certain topic in.
It's pretty obvious that the altcoin section or off topic section will be neglected when there are a lot of reports on the other parts of the forum such as Bitcoin Discussion (just an example).
First off, I understand that the moderators on here most likely have real jobs and a life in some cases. That's not the issue. I was just stating how multiple posts would tell the moderator to lock the thread because the OP hadn't been active online in weeks when it came to his giveaway! And unfortunately this went on for a few more weeks until the thread got pushed to the back pages. Maybe you just came across better luck or had a moderator who was more proactive.