The person making the hiring/firing decisions probably isn't responsible for the bottom line. They'll be working within defined constraints on what they are authorised to do and how much they are authorised to spend on doing it. If they want to go outside those constraints, they probably have to follow a standard procedure to request authorisation to do so, which may well involve legal as well as accounting approval, explicit approval from management at increasing levels of seniority depending on the request, etc.

If senior management haven't kept a careful eye on how their policies are actually being implemented, this can easily create perverse incentives where doing something is favourable to the person making the decision even though it is less favourable for the overall success of the organisation. The current example, hiring expensive contractors for very long term gigs instead of salaried staff, is not unusual.

Other similar results of potential interest to geeks would be things like renting SaaS rather than buying (often more expensive in the long run, but done because the relatively low recurring opex is preferred to relatively high up-front capex) and buying commercial software from a preferred supplier rather than using something Open Source for free (because preferred suppliers have been pre-vetted and approved so their product can be bought immediately, while using someone's FOSS might need legal to review the licence if it's one they haven't seen before, which can involve all kinds of "business justification" paperwork and extensive delays).

Edited to add: Of course, there may be other factors as well. Contractors might be more expensive per day but often don't come with the long-term legal obligations of hiring an employee (a big deal in places with relatively strong employment rights laws, such as most of Europe). For software purchases there may be issues of ongoing support contracts or (re)training and migration costs that dominate the total cost of ownership, making rent/buy or COTS/FOSS decisions a relatively minor factor. Sometimes the incentives set up by senior management who are looking at the big picture aren't as perverse as they look from below.