It's a play on words. The great grandparent suggested hiring a coach, i.e. a mentor or instructor, to improve his skills. The word coach, shortened from stagecoach, also refers to an intercity bus (what I would have called a highway bus as a kid). So, the reply is suggesting taking the bus to another city where jargon like "velocity" is not used. It suggests the problem is the company culture rather than the individual. I thought it was quite clever.