Question: why not use timers?

I have a concern about polling SQL Server too often. By default SQL will be polled every 15 seconds, which means that jobs are not executed at the exact time they were set. I understand I could set the PollInterval to 1 second but that would mean calling SQL every second. That seems to be a lot.

I am just wondering why Hangfire was not implemented with Timers. Using a timer, you would not need to call the database every second or every 15 seconds to get the next job to run.