My 2008 ZZR600 sat for over 2 years, and when I turned the key nothing happened, even with a new battery added.
I put it in first gear and pushed the bike forwards and backwards with the clutch lever out, until the back tire was skidding on the floor. It worked- the starter began turning the engine.
Then I had to deal with old improperly stabilized fuel in the gas tank after the engine started, after several seconds of cranking.
At least you learned quickly and cheaply which mechanic to not trust.
“It is difficult to get a man to understand something, when his salary depends on his not understanding it.”
― by Upton Sinclair, who helped clean up the meat packing industry and other factories