[mrzimmerman]

Guilds and unions aren’t in place to prevent nepotism, which is difficult to prevent and happens in all industries. Really, that’s just a network effect, albeit a bad one.

Labor organizations exist to turn disparate sources of a supply (labor) into a more monolithic source that can control some or all of the access to that supply, driving up the price, which is good the members. They may have controls in place to try to prevent nepotism or other bad hiring practices, but at the end of the day that can be a difficult problem to detect and prevent.