BcalcOS is currently created and maintained by one person. That is something to consider because choosing a Linux distribution is also choosing who you are relying on to maintain it.
BcalcOS is my personal Linux project: I use BcalcOS myself every day. That gives me a pretty good reason to keep it maintained. It wasn’t created solely for an audience of other people. It is the system I build, use, and continue to develop.
But probably even more important for users is the fact that BcalcOS is not built from scratch. It is based on Devuan, an established Linux distribution with its own developers, packages, repositories, and infrastructure.
That distinction matters if BcalcOS were ever to stop being actively developed. A BcalcOS installation would not suddenly cease to function, and the underlying operating system would not disappear. Users could continue receiving software and security updates from the Devuan ecosystem and could continue using the system they already have.
Things specific to BcalcOS, such as the Quail custom applications, third-party app packaging, configuration, and branding, do of course depend on continued BcalcOS maintenance for updates or revisions.
The same is true of some of the non-Devuan default technologies BcalcOS chooses to use: Brave Origin and XLibre. Brave Origin is unlikely to be going anywhere for the foreseeable future, so it is not a particular concern. While I am a proponent of XLibre, its future is not guaranteed. If BcalcOS development stopped and XLibre then stopped being maintained as well, a future user could have to move to another display-server technology without BcalcOS providing that transition for them.
That is a genuine limitation of a small distribution. However, this is very different from being completely dependent on a one-person operating-system ecosystem. BcalcOS is built on an established foundation, and much of the software running on it comes from that larger ecosystem.
TL;DR
BcalcOS has one maintainer, but it does not have one source of support for everything on the system.
If the bus did finally get me, users would still have a functioning Devuan-based system that could continue independently of the BcalcOS project.