This is because modern political libertarianism was literally financed by fossil fuel and tobacco billionaires who opposed all regulations; especially health, environmental, and labor. They seized libertarianism as a means to destroy the government. Prior to their takeover in the 70's, Libertarianism was considered to be progressive.
Most libertarians don't know what libertarianism is, because they are conservatives who believe their narcissistic "fuck you, got mine" conservatism is libertarianism.