I'm not sure there isn't a counter-argument to the first part, as I really don't know the science, but if the virions travel via droplets or aerosols, isn't it the size of those that matter rather than the size of the virions?
However, the last part where he talks about touching the masks is 100% spot on. I linked somewhere to an Israeli article about possibly exempting students from wearing masks during extreme heatwave, and there's a video interview with a doctor there who says the same thing. Constantly touching a mask, which is what most laypeople would do, especially when uncomfortable, is probably worse than not wearing one at all.