It's an interesting part of corporate culture. Large companies hate the process of firing employees for a number of reasons: staff moral, public perception, potential legal liability, etc. This applies whether it's individuals for performance reasons, or entire teams for economic reasons. To avoid this, there is often a lot of (bureaucratic and difficult) process to justify the hiring of a new FTE.
The corollary to this is that it's often a lot easier for a manager to hire a contractor or use an out-sourcing vendor, even if they don't see the requirements of the role being any different than that of a "permie" and even if it costs the company more money.
The corollary to this is that it's often a lot easier for a manager to hire a contractor or use an out-sourcing vendor, even if they don't see the requirements of the role being any different than that of a "permie" and even if it costs the company more money.