I didn't redefine the term.

H1-Bs go to people who are often already immigrants or will soon be. Does that help?

No. By definition it's a non immigrant Visa. I've known plenty of people who come in on a tourist visa and convert to a green card. That doesn't make the tourist visa into an immigrant visa. The EBs are the immigrant visas.

Immigrant visas (for permanent residency)

Purpose: To live permanently in the United States.

Employment-Based: Based on a job offer or investment.

EB-1: Priority workers, including those with extraordinary ability, outstanding professors and researchers, and certain multinational executives and managers.
EB-2: Professionals holding advanced degrees or individuals with exceptional ability.
EB-3: Skilled workers, professionals, and other workers.
EB-4: Certain special immigrants.
EB-5: Investors who create jobs in the U.S..

Diversity Visa: An annual lottery for individuals from countries with low rates of immigration to the U.S..

Non-immigrant visas (for temporary stays)

Purpose: To be in the United States on a temporary basis for a specific purpose.
Examples:
Tourism: B-2 visa.
Business: B-1 visa.
Temporary Work: H-1B, H-2B, L-1, O-1, P visa categories.
Study: F and M visas.
Exchange Visitors: J visa.
Fiancé(e)s: K-1 visa for those intending to marry a U.S. citizen.
Spouses: K-3 visa for spouses of U.S. citizens who are waiting for an immigrant visa to be processed.

A non-immigrant visa is for a temporary stay and has an expiration date.