Sad. But a perspective from a longtime youth sports activist:
On the one hand, it almost certainly won't be improvements for that one week tournament. The improvements will enhance local use, and once the local DY organization has hosted a national tournament they'll hold state and regional events in the future. It'll be something of an economic boost many times over.
On the other hand, $3.5 million???? With 24 teams, thats about $10,000 for every player or coach. Families come along, but no one's spending $10,000 for a week at a baseball tournament. Mostly moderate hotels, eating out, and hanging around the sports complex.
It is a sad reminder, though, of how low on the totem pole disc golf is with most parks departments.