Think of Linux as a consortium. Businesses/individuals get together to address a common computing need or problem. They may chip in labour or money, hire a technical leader or team, or otherwise cooperate to make Linux address their requirements. The solution is totally theirs for keeps, and it does not have to cost a lot--they can re-use the pre-existing Linux software pieces. They may even cooperate to overcome the advantage that a big "industry leader" may have and use against their interests.
Linux is the end-product of activities of many such loose "consortiums" who "scratch their needs." So Linux is a business, but it is not necessarily about centralized production and marketing of software. It is a de-centralized, small-scale development performed close to the end-users, so that they have access to reasonably-priced software that matches their need, solves their problems, sells their hardware or service, and which is totally theirs to keep: the licence never expires, and the user will never be cut off.[an error occurred while processing this directive]