Stack Overflow frequently is on the first page of Google search results and I am surprised how often the valuable question has been closed for being off-topic despite numerous up votes and answers with up votes. How many points have topics closed for being off-topic received? Is there data to suggest that questions with points and quality answers should be re-opened? Should those who vote to close a topic that receives traction be "punished" when there are more people who find the question and answers valuable up vote more than votes to close?
Upvotes aren't really indicative of an on-topic question. They are indicative of a question that people may find useful, funny, or cool, but that's pretty much about it.*
Should those who vote to close a topic that receives traction be "punished" when there are more people who find the question and answers valuable up vote more than votes to close?
Think about what kind of a signal this would send. You would create a punishment for those users who care most about the site (and have earned the privilege to vote to close, something they get no reward for) on the basis of votes (which practically anyone can cast). It's difficult to think of a more effective way to discourage community moderation altogether.
* A huge fight was had on Meta over the past two years concerning what should happen to off-topic questions. There were two main camps: the deletionists (who argued that any off-topic content needs to be removed completely), and the those who argued that while off-topic questions need to be closed, they shouldn't be deleted altogether, but perhaps archived. Unfortunately, the deletionists won, so the current policy is not only closing but also deleting all off-topic content.
Getting the Data
You can do this using the Data Explorer though you may have to limit your query to a few months due to the volume of data and the limitations before something times out. Using this query counting closed questions with score over 0, I got a total of 480,607 score on closed questions, which means there were at least 2.4 million reputation gained on close votes (score is the sum of up- and downvotes, and it takes 2.5 downvotes to equal an upvote reputation wise, so the 2.4 million is the minimum in this case and is likely higher).
Why the Data is Useless
On-topic and upvoted are not correlated. An amusing off-topic post in a popular tag will likely get far more upvotes than a very good on-topic question in an unpopular tag. Judging usefulness or topicality based solely on score is probably not the right decision.
Just a couple months ago there was a whole lot of hubbub on buying croissants. The question has since been deleted, but needless to say it was quite popular. It was also off-topic.
Batch re-opening highly scored closed questions is (re-)opening pandora's box.
What You Can Do to Rectify the Situation
If you find glaring examples of a great highly-scored question that is on-topic for the site, you can cast a reopen vote and stick it in the queue where the community can decide. If you don't have the reputation to cast re-open votes, you can make a meta post asking why it is closed, and the community can vote to re-open it if they agree with your assessment.