That's true, but making flying even more miserable doesn't sound like a very good strategy to fill those planes. I would understand it if it was an actual safety measure backed by science, but in all honesty we all know it's just a gimmick.
For me personally, this means no flying (with KLM at least) until the end of summer, even though I had many travel plans and I was willing (even craving) to go ahead with them. And since KLM is one of few airlines that still runs a reasonable network, I was planning to fly with them. I don't have a medical condition (hence no exception for me), but I struggle to breath in the mask and will get dizzy after couple of minutes. I simply can't wear it for 3 hours.
The way I see it, many in travel industry believe the way to revive leisure travel is to introduce meassures that will boost people's confidence to travel. I don't think this is gonna work. People who are afraid of the virus will not opt to travel just because other passengers wear masks. And on the other hand, people who don't share this fear and would be happy to go on a holiday will be put off by the misserable experience, having to cope with all this nonsense.
With business travel not recovering anytime soon, I don't see how this could work.