What employers pay employees and independent contractors (which is what most columnists are) is between them, just as your salary is between you and your employer. 

A writer's work, like that of every worker, should be evaluated on the quality of what he/she produces, not the amount of their paycheck. A hack is no less a hack when overpaid, just as a great writer is no less great when underpaid.

If you think what NCR produces is worthy of support, then make a contribution. Otherwise, don't. Either way, you have no right to know what individual employees are paid.