I get the idea of log books, and I don't disagree.
But...
Lots of old dirt bikes simply get dragged out of sheds, given the once-over and are taken racing.
Demanding that they all have log books will be a crimp on that, and will likely reduce participation.
If there's a requirement for bikes to be taken to an inspection before the logbook will be issued, then this will make the problem even worse, particularly for us punters who don't live in a large city.