I'm not going to go on and on but here's the thing...when you click on this map some really useful information appears but:
poor symbols that don't differentiate
poor reference backdrop that just adds visual clutter
overlapping symbols at small scales that just creates visual noise
The map needs far more nuanced design to enable it to operate as a multiscale information product. Some form of aggregation at small scale that then proper symbol design to differentiate meaning between different classes. Maps like this are lazy. Yes, good maps take time to create but this sort of map does a disservice to the information behind it. Who will stay to interrogate this map? Answer...very few...they're off to another web site.