It's more like he wants a fast car but doesn't want to deal with servicing it. So it might fall apart in six months, but that's something he is OK with.
Julia's target audience is technical computing, and a large fraction of software in this space is built to solve a particular problem that only might matter for 6 months or a year. You might be trying to simulate the behavior of an experiment you just designed, for example, or trying to analyze a very specific property of a data set. These codes are often very tightly coupled to the scientific problem, and are only ever used in the context of a particular short-lived project. You do the experiments, write the paper, and move on with your life.
To be clear, I don't think Julia itself encourages this pattern any more or less than another language. But it's a very common pattern for scientists, so they often don't care about long-term maintainability.
Granted, this sometimes comes back to bite them later, if they discover the old code is good for a newer experiment, or they need to go back and re-validate results. But this doesn't always happen, and it's not like they're running a live service with customers -- when they finish a given paper, it's actually not unlikely that no one will ever need to use that software again. It's not easy to argue that they should care about maintainability when there's a decent chance this is one-off code.