why does GM do this stupid shit?

[clutchdust]

Unlikely that this is the case, as these bolts are present on all four joints on both halfshafts, and also on the propellorshaft.

But for me this discussion is now closed, as your attitude seems to be that a n00b got to be wrong and does not know what he is talking about :zzz:

That will work well both ways as you have, 1) proven your car is not as it left the factory, and 2) you want to take shots at someone without knowing the facts.
The factory bolts for the driveshaft (propeller shaft) are 12pt bolts, as you stated. However, the bolts on the halfshaft assemblies are a larger 6pt inverse Torx. If your car does not have this arrangement, it has been previously "fixed" by someone else like Red, fixing stupid shit the GM engineers did.
Either way, it doesn't change the fact that GM decided to solve a problem that wasn't there by creating an uncommon fastener that offers no improvement over currently available fasteners. It may have been the idea that they can get the average guy to go back to the stealership instead of doing their own work, but it rarely works that way. Instead, you get what Red has now, some backyard monkey who's hammered a socket onto those craptastic bolts trying to get them off. When they are successful, they end up just hammering the socket back on to reinstall the same crappy bolts. When not, they generally screw every one of them up trying to get them off so later on the next owner has mangled fasteners to deal with.