The author never assumed that high wages allow people to obtain every good they want. Even if they don’t, the survey results can still indicate that financial rewards aren’t the strongest incentive when choosing jobs.

This establishes that for the exact same job, people prefer higher wages. But the author never assumed people don’t care about money at all. The author’s position is that money isn’t the strongest incentive. But it can still be an incentive.

This points out that “financial rewards” can include other aspects besides a high salary. For example, stock options or bonuses. This shows why the survey results, concerning only salary, don’t show that financial rewards are not the strongest incentive for people choosing jobs.

This points to something else people value about a job. If it does anything, it goes in the direction of supporting the author’s position that there are other parts of a job that could be a stronger incentive for choosing one job over another.

This suggests that for some people, they don’t know ahead of time the downsides of jobs with high salaries. This doesn’t point out why the survey results don’t support the author’s conclusion.