Well, remember that just because a company is democratically controlled does not mean that its member-owners cannot elect an executive hierarchy of its own. But when the votes are cast for that election, it will be the member-owners' interests that are being reflected, and not outside investors' interests.
To give an example that's more to do with worker cooperatives, suppose the member-owners are discussing whether to work 35- or 45-hour work weeks. The 35-hour work week might be good for work-life balance, but bad for the business itself, while the 45-hour work week might be the reverse. Nevertheless, the majority of members might vote in favor of the 35-hour work week, and whether or not that is bad for the business, it will be good for the majority of the workers.
Granted, the democratic process isn't perfect -- you need only look at U.S. politics if you need proof of that -- but when you compare it to its alternatives, it's not at the bottom of the pack.
To give an example that's more to do with worker cooperatives, suppose the member-owners are discussing whether to work 35- or 45-hour work weeks. The 35-hour work week might be good for work-life balance, but bad for the business itself, while the 45-hour work week might be the reverse. Nevertheless, the majority of members might vote in favor of the 35-hour work week, and whether or not that is bad for the business, it will be good for the majority of the workers.
Granted, the democratic process isn't perfect -- you need only look at U.S. politics if you need proof of that -- but when you compare it to its alternatives, it's not at the bottom of the pack.