To say Apple's Cork presence is just a pretense is largely inaccurate. I've been to the Cork campus numerous times while I worked for the company for seven years (2005-2011). The campus was, and is, still a huge base of operations for Apple. The majority of their AppleCare international support is based there (both support personnel and management/exec), as are many other departments. There are, literally, hundreds of people there from all across Europe who have relocated to Cork.

Beyond the main Holyhill campus, Apple has a large amount of office space within Cork's city centre.

Additionally, Apple also has a pretty big assembly line there. Many of their products have also been (and still are) assembled there. For many of the PowerPC and earlier Intel machines, if the serial number started "CK", it was assembled in Cork (it's been a while since I've memorized Apple's serial number structure, but they used to be much easier to parse).

However, the area of Cork that Apple's campus is located isn't very affluent and suffers like many inner-city boroughs in Ireland and Europe. Ultimately, the state of the roads isn't Apple's responsibility. You'd hope that a company like Apple could lean on the local government to improve it, but Apple wasn't the company it is today, back in the early 2000s. It was getting there, but it was still coming out of the near-bankrupcy 90s.