There are so many reasons to leave a job. I can only say why I left jobs or rejected job offers in the past:
- Left a bullshit job. I was bored.
- Left a job because I didn't like where I had to live.
- Left a job because the company was unraveling. It went under within a year.
- Let a job because of incompetent management and crappy code.
- Rejected an offer because the place felt like a morgue.
- Rejected an offer because the hiring manager's boss acted like a entitled asshole.
- Rejected an offer because the work spaces for developers were even worse than open plan.
It's about Punch Tape. Old Teletype terminals allowed P-tape to be "written" and read. If the typist made a mistake, they could back up the tape and type "Rub Out." That would write a DEL, effectively punching holes across the tape - effectively a bitwise OR. P-tape readers were designed to ignore the DEL.