The main reason that the British government would conduct general searches of colonist's homes and businesses was to find smuggled items that were not taxed.
During this time, Great Britain was putting taxes on the colonists. This was in order to pay for the very expensive French and Indian War, along with continuing to supply the colonists with British troops to protect them. Even though Great Britain had their reasons for the taxes, the colonists still opposed them and felt like they were unfair. They had nobody to vouch for them in the British Parliament, which is known as "taxation without representation."
This would cause many of the colonists to boycott products that contained the tax and even smuggle items without having the tax on them. This started to become a problem, so British troops would search businesses and homes of the colonists, searching for items that were supposed to be taxed. The colonists hated these searches and it deepened their hate for Great Britain in general.
This eventually led to the Fourth Amendment, which protects citizens from unwanted searches from the government.
