I fond it works to have a division of labour between builders and maintainers. Just like in property management, the different phases need a different approach.
If builders don't experience the maintenance costs of their decisions, how will they ever learn? And even if they do learn, where's their incentive to do it better next time?
You limit builders by forcing anything they build to hold an alpha/beta/preview label, where it doesn't graduate to having the full backing of the company if maintainers can't fill in the rest of what's necessary for long-term maintenance. The incentives revolve around how many "builder" projects eventually end up losing the alpha/beta/preview label and how long it took to lose the label.
Maintenance concerns should be part of the requirements for the project to be considered successful, the same as pretty much any other engineering. If the only reason to have SEs care about maintenance is to have them do it later, then incentives are wrong.
Communication between the builders and maintainers, including "costly signals" (commercial consequences for poor work, poor reputation, losing contracts etc). There are a lot of builders out there.
