I find myself with a distinct lack of 10K-itude, so I'll have to go on what bwDraco says of the answers. Let's look at the guidelines for historical locking.
A historical lock preserves older content that was very popular when it was originally posted, but is now off-topic or otherwise out of scope for the site it is posted on.
It appears from this question that the question in question was indeed quite popular. It was also too broad, but was always so.
Questions can be historically locked when:
- The post is Off-Topic or Not Constructive, and
- The post is stellar, in spite of its off-topic nature, and
- There are a large number of views, upvotes and inbound links on the post, and
- The post is contentious; i.e. it has been closed and reopened at least once, or deleted and undeleted at least once
The question was indeed not a good fit for the site, given its broad nature. Condition 1 passed. Given the fact that it received boatloads of upvotes and views - and, more importantly, it got great answers - it could be considered stellar, and it would be a shame to hide the knowledge therein from Googlers. Conditions 2 and 3 passed. That last condition is tricky: it appears from this bwDraco's description that it was unambiguously recognized as unacceptable and disposed of without dispute.
Let's make sure that we're not violating the "do not" guidelines for historical locking:
Questions should not be historically locked if they:
- Are being actively maintained, or
- Have little or no redeeming value.
The post is certainly not being actively maintained; it's deleted. Condition 1 passed. Though the question itself may not be too useful, the answers are. Again, deleting good content (especially content that has attracted so many views) that was in response to a bad question would be a shame. Condition 2 passed.
Except for not being contentious, the post fits all the guidelines for historical locks. I would argue that we should undelete and lock it so as to simultaneously preserve the knowledge and make it clear that we don't accept such questions.