Maybe for the person writing the timer, definitely not for the person implementing them.

which is more?

More what?

Are there more persons implementing the timer or more sysadmins using the timers and specifying timer syntax every day?

For some people, myself included, on a long enough time scale you end up working on every piece of software on their system. In this case the simplicity is valued.

Different tools suit different people. Cron isn't dying any time soon just because the casual Linux user is better served by systemd.

Are you saying you have committs in cron, SysV init and in the Linux kernel?

No. But I have commits in lots of things and I've definitely dealt with the code of several cron implementations and the Linux kernel, among other kernels.