Permanent body modifications required to do a job? Yay! Especially yay as it's only for identification purposes, much like nazi slave bar codes
Additionally, having injected microchip increases possibilities for an external attacker (as long as it doesn't do cryptographic authentication) as opposed to having something to carry with.
The only advantage seems to be that you can't give the access badge to someone else if it's injected into you, so it seems this measure exists because the company doesn't trust its own employees. And if they aren't trusted, it's pretty damn pointless to let them in the data center anyway. So, doh!