I feel like he should use it, obviously it's better for the environment, however considering the times we're in it's probably best to stick to driving (thus avoiding mingling with the masses on public transport...)
That might be his reasoning for it and he may simply not want to admit it; I know that most, and I mean most people that I know, refuse to use public transport at the moment. I support them for it and don't blame them at all: the less the better for me >:P
Anyway, it may not be great for the environment, but given the number of yobs riding the buses without masks, much less that jack*** that decides to sit right in front of you or right behind you (who proceeds to cough) it seems suitable, at least for now until things get normal after a while.