People who do risky jobs even in the best of times, are used to making certain calculated risks. For them there isn't a question of whether or not they will take the risk but how they can get their job done as safely as possible.
I think in the last month we've been so bombarded with Covid19 horror stories, that we've become a bit desensitized to it. Most of us are sick of being cooped up and if we aren't in high risk group, we are willing to take our chances.
Since in this case, the enemy is unseen, certain taxi drivers and others who are used to real time dangers, are probably finding it easy to go on about their business and hope for the best. It seems to me that they could at least wear a mask.How hard is that to do?