The videos are like lecturers in university. You sit down and listen and pay attention. You shouldn’t be doing anything else.
You may take notes. Unlike a human lecturer, you can always pause the video; this is actually advantageous. Thus, the subtitles should present no obstacle whatsoever.
As for typing code, you don’t do this from the videos, though if you really want to, you could (just pause the video). All the written material is bilingual, so again this should present no obstacle.
I don’t disagree that English is the lingua franca of the world. But given that most people on the planet are far more comfortable in their native tongue than in English, it’s actually helpful to have English subtitles that they can read, as listening to English can also be problematic.
Imagine foreign students who come to America to attend university. Their command of English may be subpar. When they attend lectures, they cannot interrupt the lecture repeatedly just because they don’t understand the phrasing of the lecturer. At least with a video, you can pause and carefully examine the subtitle.
Obviously, the instructors of the Pharo MOOC are French. They should speak comfortably and clearly. They wouldn’t be able to do that in English (despite being lingua franca). Under the circumstances, this is understandable and acceptable.
Perhaps somebody in the US or UK can present a similar MOOC in English. Until then, we still have a useful educational tool here. I wouldn’t obsess over this.
UPDATE: I just learned that the new Pharo MOOC will be dubbed in English. “Problem” solved!