Gotcha.
The only thing I can say to that is that every organization needs to assess what the risks are to its operations; if a local bus service doesn't think it has any liability exposure for its riders getting a disease from other riders, then it could rationally decide to keep transporting people. Nobody has to take the bus . . . it's on the would-be rider to decide whether to take that risk.
The NBA is a pretty good alternative to that scenario, where you have a highly paid, rare talent/size athlete in Rudy Gobert contracting coronavirus, and if he were to play a game against others before showing symptoms then he could infect the entire league, directly or indirectly. The NBA looks at that and says "short term pain for long term protection against greater pain" and suspends the season . . . that makes sense to me.
The NCAA is sort of in between the NBA and the bus scenario . . . the tournament is far enough away in time that the NCAA might come up with controls over how the tournament proceeds with deletion of fans in the stands (check) player health checks/doctor certifications, liability waivers and the like, and they might be able to attract enough schools to participate and keep the 2020 TV money. Some schools not that invested in their basketball program might not accept invites . . . that's OK. The key in a decision to proceed with tournaments is serving the overall brand by playing.
I don't mean to put words in your mouth, but your perspective seems to be that the March Madness brand - nnd the bus company's brand - might be besmirched too much to continue . . . that's an entirely valid point of view. It wouldn't shock me if that perspective were to prevail and the NCAA ultimately cancels the tournaments, the next month of the baseball and softball seasons, the track seasons and so on . . . and it wouldn't surprise me if buses/trains/planes and taxis were to suspend operations for a while. In this situation, all of that is on the table, and reasonably so.