So it was an hourly probationary period? I can't see why one would opt for salaried if hourly was on the table - in my experience I never work less than the assumed salary hours.
I'm actually not that sure about the rationale. It wasn't optional - their offer said "$52.88/hr for the first 12 months, $110,000 a year after the first year". I'm not sure if it's to incentivize working more the first year, whether it's "probationary" (in case the person doesn't work at all?) or if there is some other form of logic to it.
Bizarre. Maybe it was encouragement to get the employee up to spend as much time as possible to get up to speed? But then again, that's incentivizing burning the candle at both ends when you're the least equipped and familiar with everything to really take advantage of it.