Earlier quoted context omitted.
H1B is a dual-intent visa, which means holders are allowed to pursue permanent residency (upgrading them to an immigrant by the US legal definition) by applying for a green card. Most people use the term "immigrant" for people who have chosen to live in another country without considering the "non-immigrant" status of their visa.
Is there some rule that says other people aren't allowed to pursue a green card? That doesn't seem like a differentiator to me. That's a real question, I have no idea how any of it really works in the practical sense.
> Persons with H-1B visas (for specialty workers and their spouses and minor children with H-4 visas), K visas (for fiancees or foreign spouses of US citizens and their minor children), L visas (for corporate transferees and their spouses and minor children), and V visas (spouses and minor children of lawful permanent residents) are permitted to have dual intent under the Immigration and Nationality Act.[1]
> Most other foreign visitors and workers, like those on H-2B worker, H-3 trainee/worker, B-1 business, B-2 tourist, Visa Waiver Program visitor, F-1 student, J-1 exchange visitor, M-1 student, journalism, and entertainer visas should not have immigrant intent. Such visa holders can be denied admission if the consular or port official reasonably believes that they have interest in permanently remaining in the United States (i.e., in pursuing a green card).