I would say "Many decades of poor deer management practices."
The previous DMP was based on 20 years of scientific research using enclosures and that research was supported by additional research on the effects of browsing by deer. The results of that plan was that the herd in 2G was at it's DD goal, when the new plan was implemented in 2000. At the same time the plan produced record harvests of both buck and doe.
In 1998 and 1999 the PGC issued 890,700 antlerless tags . In 2000 Alt reduced that allocation to 830,650 tags and in 2001 he reduced it to 780,250 tags. And after that allocation reduced the herd by 8% he increased the allocation to over 1M and after a 40% reduction in the herd the PGC is still issuing more tags (plus DMAP Tags) that were issued in 2001. Please point out the science that supports that insanity.