Many people believe if you can't program, there is no reason to have access to the Source Code because you would not understand how to use it anyway.
But when Users have at-cost access to the Sources they can then hire anyone with those skills to operate, or fix or improve those Sources.
When Users are allowed at-cost access to the Virtual Sources of Production (such as computer source code), competition between potential workers is maximized because nobody can stop those users from trying to do it themselves or hiring anyone they can find to do that work. Under these conditions, wages drop to nearly and often even completely to zero!
This is also true for Physical Sources (such as land, manufacturing plants, buildings, tools, etc.).
If a group of passengers co-own a car, bus, plane, ship - they must pay all the costs, including any wages for work they don't do themselves, but when one of those passengers knows how to operate those Sources, he will likely do it for free if he wants to arrive at the same destination (if he is scratching his own itch).
But it is not just wages that fall. When Users co-own the Physical Sources of Production, again - they must pay all costs, but since they are treating the product itself as the return for that investment (the product is not even sold), they do not and even cannot pay profit, for who would they pay it to?