Disclaimer: we still have pragmatic reason to follow the evidence suggested by our best scientific theories. I'm just poking fun at scientists in the spirit of Hume. There's no guarantee that the future will resemble the past, and even our best scientific theories are amenable to future evidence.
Fair enough, the meme wrongly implies that scientists don't know about this uncertainty or would be mad to learn about it. That said, my impression is that most scientists, even if they are aware, are not philosophically inclined enough spend time thinking about it. Which is why we still have a philosophy department.