Getting fixes into the game is a production line process. It passes through multiple hands to get into the live game - reproducing the issue and documenting the repro steps, the development to fix the bug, peer review of the code to verify the fix, QA testing to verify it functions as intended, catch edge cases, and re-coding to account for found issues, localisation to translate any text into German, French and Brazilian-Portuguese, scheduling, upload management, re-testing of the release build by the Release Candidate QA testing team, editorial of the patch notes.
We make game jams available to all staff involved in that process to flex different creative skills, and therefore the release process shuts down for the week of game jam so the release team can also contribute to game jam projects.
If I chose to not participate in last week's game jam and instead use that time to fix live bugs, they still wouldn't have released this week, because the production line was turned off for a week, to give us permission to game jam. At best I'd create a backlog of initially deved fixes for future processing through the production line when it's re-manned the following week.
I can entirely understand the surprise and disappointment, as regularly scheduled game jams are a new thing we're trying, and I sympathise with the news post editors who deal with the fallout when we down tools for a week. Especially as we can be cautious about talking about the fruits of those game jams too soon in case it creates expectations of imminent release.
As a developer, I'm appreciating the creative outlet and a space to explore game health projects that are bigger than bugfixes, require more complex solutions than ninja strikes, and outside the scope of monthly headliners on the release schedule. I very likely aren't working on the thing you consider the game's most important priority fix, but I'm getting to fix something that I've really wanted to fix for years, and haven't 'til now had the opportunity to do so (or even explore the potential of doing so).
Game jams are experimental and only a fraction of what's explored is going to be green-lit for release, lead to practical outcomes, or shippable in its first iteration, but game jam provides us a platform for lean passion projects that can have an extremely good return on investment, and I'm very grateful our leadership team are scheduling time to make game jams available to us.