Grave digging for topics: what are your thoughts?

What are your thoughts on say a new (or old member) looking through all of the topics on a certain part of the forum & then posting in an old topic that hasn't been posted in for maybe a year or more? Most forums I've been to despise when members do this & usually tend to ask that members not grave dig, where as some other forums actually encourage it.

What do you think about posting in a topic that hasn't been posted in for a while? :3

I don't care at all, if somebody just wanted to respond to some old topics or create new discussion in them, why should it be a bad thing? I really never understood why people got mad on other forums about doing it really. On here I never really noticed anyone getting mad though, and I of course allow it to be done.

I have not seen anyone post in a really old topic on here for the most part. I have seen many places that only keep the topic open for 30 days if there's no recent post.

Generally I see people's opinions change over time, so when someone new posts in an old topic some people will repost giving a new opinion to that topic, plus it would depend on the topic, it'd be kind of ridiculous to see someone say welcome to another in a year old welcome post.

I don't really have a problem with it. However, if I want to discuss an issue that hasn't been discussed for a long time, I prefer to start a new topic rather than gravedigging the old one, because the posts made in the old topic will no longer represent the opinions of the people who made them. 

Another thing I don't like - and actively discourage, but don't forbid outright - is reviving old news threads. That can be confusing.