From the 2008 article: The Bradford's supposed sins are laid out like an indictment in a government resolution under consideration by the Prince George's County Council: Its weak limbs break off and litter roadways. Its invasive nature causes the tree to aggressively reproduce and push out other species. It's not native, its ancestry instead rooted in China.
Esther Mitchell, coordinator of a county gardeners' group that pushed for the resolution, puts it more simply: She calls the Bradford "a weed tree."