It's because it is huge. Compared to a normal desktop monitor, he is looking at like 30 point text. If you were to render text as the same size as a normal monitor, it would be illegible on a vive (which is what it looks like he is using). The thing is, when you have near infinite surface area, having big text is no big deal.

It'd be interesting to see how the eye damage/strain caused by reading small text on a big monitor compares to the eye damage/strain caused by reading big text on monitors inches away from your eyes.

I was wondering more about screen door and texture aliasing effects because of barrel projections, etc.

Thx for the note on the vive