Because the article is exaggerating a bit. There was no formal lease, just an unwritten 'agreement' that the Scouts could stay for a buck a year. Legally the city is well within their rights to cancel the agreement, and I believe that they are claiming that anti-discrimination laws require that they do. As for the Scouts, they are finding out that in God they should trust but for all others put it in writing.
Interesting. But I thought oral agreements can be binding too.