Businesses will generally be in favour of immigration. A business is not trying to increase GDP per capita. They will be happy with an increase in GDP, even at the cost of a decrease in GDP per capita, because this will increase their revenues and profits.
Businesses and their owners don't pay the external costs of immigration: more crime, disease, litter, car crashes, lower average IQ and therefore a lowering of the sophistication of the society (its ability to run complex systems like trains and power stations), and fewer inventions in the future. The business owners don't have to live near the newcomers.
And what about the people who just want to live near people like themselves? Diversity has a psychic cost, not paid by businesses.
Some immigrants are bad for society overall, but their costs and benefits fall on different people.