I haven't seen this in practice. For my site, roughly 100% of the new additions to our database come from people climbing a route that's in the Big Database that we just don't know about yet.

It's just a matter of dropping a link to that route's page into an importer to scrape it in and have it be usable at our end.

But yeah, for a space where the Big Database didn't often have a record for the things your users want to add, I could see it being more of an issue.