Also, there is some arrogance in assuming that all those depressed people just _haven't thought about_ cycling to work, or listening to a podcast, and should just pull themselves up by their bootstraps to start feeling better.
Not everyone gets to make lemonade out of lemons. For one thing, you need to be able to afford sugar (_but it's cheap to me!_). For another, you need to like lemonade in the first place.
Besides... Correlation is not causation, and the depression might not be a direct consequence of being bored on transport. Perhaps it's because they get to spend 30 fewer minutes with their family, pets, or hobbies. Perhaps it turns out people with longer commutes tend to have worse paying jobs, or live in areas with less opportunities for recreation (even a local park counts). But I think it's at least plausible that lengthening your already-too-long workday by an hour can't possibly make your life happier.