Because “for years” that was the restriction. That doesn’t sound like much of a restriction. The implication is that it’s restricted less now. The story talked

Because “for years” that was the restriction. That doesn’t sound like much of a restriction. The implication is that it’s restricted less now. The story talked about how San Francisco resisted high rises for a long time, so that restriction doesn’t follow the story — that’s why I think it’s a typo.