Jenkins and many other tools are designed by developers, there needs to be a word for that... we just call it "developer design" - functional but ugly.
In a lot of cases it's only functional in the sense that it performs a function. To me functional but ugly implies a certain sort of delusion that while it might look ugly, it is really efficient to interact with, so therefore, it doesn't need to look nice. This is often not the case though. A lot of these developer designed interfaces end up being confusing, hard to navigate, and ugly.
Jenkins is especially bad with the transparent logos overlapping the butler image. A lot of developer designed tools have a simplicity like Hacker News or infinite possible customizations like X windows. Jenkins has neither of these attributes and often just seems painful to use
To be fair they're working with a completely different set of constraints than this is - this is close to the Delta ticket redesign project if you could also use it for your delta ticket. They have to support every browser, every language, every platform, every ARIA recommendation, and make sure that everything is open source compliant, which is fairly tricky.
