Whether unions are, or are not, good and necessary is always a matter of much debate.

Within the railroad industry, employees of a company that is unionized typically have greater income, better H&W benefits, work rules and conditions, and a griveance process that employees of non-unionized companies don't have. That's why the employees of so many shortline spin-off's from Class 1's vote to unionize, not the other way around. For example, a well-known regional railroad in Oregon was non-union when it first stared. It was unofficially known as the "Foamer Pacific" because of the high number of railbuff-oriented employees and the employee-friendly attitude of its management. After the guy in charge was forced out, things changed, and the operating employees voted in union representation.

As illustrated by this thread, by working for a unionized railroad, Robert has a means to pursue the earnings he feels he was not properly paid. Good luck doing that on a non-unionized property!

Disclaimer - I've worked for 3 railroads in the last 39 years (SP, Amtrak, UP), all of which are unionized, so I may be biased.