This is by OSM policy, which wants an individual (in this case, you) inspecting everything. It isn't fair to blame public data sources for this. OSM policy makes it incredibly difficult to import data from public sources like this. OSM could change this, if they wanted to. If we want more high-quality data out there that integrates with public data sources, we should make it easy for them rather than putting barriers in front of them.
Sorry, but in this case I'm not talking about public (eg: gov't, et al) data sources. For most of the MTB trail guides out there (eg: MTB Project, Trail Forks) they ask users to submit trail data then they keep it locked up.
I'm particularly bothered by this in the case of MTB Project which works with IMBA, a non-profit, yet doesn't share the data back with the greater world.
