Apple is much less concerned with pro users than with "prosumer" users, and in their case, it would strongly prefer that those users simply buy new Macs every few years than attempt to upgrade their existing ones.<p>While there is a legitimately big pro market for Macs -- especially in the creative professions -- those companies tend to follow a buy-and-replace strategy. There just isn't a lot of upside for Apple to be in the business of servicing individual pro users.<p>I say this, rather sadly, as the user of a 17" MBP that I love, and that I will use until the day it can no longer reliably boot up.
Pentalobes have been used in MacBook Pros since 2009.<p>It's not that hard to replace them, you can pick the screwdriver for the Retina MacBook Pro and Airs for $12.95 from iFixit or as part of a set of different drivers. You might even find it cheaper on Amazon.