If your compensation as a programmer or a DBA is aligned to a certain vendor / stack then you should be hoping that the salesperson is competent and very well paid. You should also not begrudge them if they do earn more than you.

IT departments might think they drive transformation in an organization but most companies view their IT department as cost centers. Enter the salesperson to sell the value of their technology, for business as usual and for the future, while trying to align the technology to the business drivers and challenges of the organization.

If the salesperson does a poor job of it and cannot make their targets then they're goneski while a programmer on the other hand will most likely earn a salary for far longer while under-performing. The salesperson who does a great job however also gets you the latest gear for the programmers to build their job security on.

I'd propose though that a developer who is independent, in demand and bills per hour probably earns as much as a successful salesperson.