I would like to browse it, and do some nice restarts from the forgotten ones nearly reached the private beta. Furthermore, I consider their deletion as an irrecoverable major information loss, and my hearth bleeds on that.
There would be a possibility to get to 10000 on the Area51. The problem is, that it is a very hard requirement, because even if I write the 5 example questions to all of the proposals, this reputation is lost with the deletion of a failed proposal, and most proposals fails. Only the proposals reached beta remain on the site.
Furthermore, having 10k+ on the a51 still doesn't mean that I could easily browse in them. Mirroring the deleted proposals from a 10k+ account would be probably disallowed by the SE, and it could be an impractical work to convert the mirrored data in a processable format (database).
So, what to do?