That's a good point. Technically you're correct about the blocksize limit not being part of the protocol, of course.
Though if everyone is running a client with a different blocksize, the network will become a clusterfuck.
No. The miners -- or rather
51% the largest group of them -- would then determine the max block size. No clusterfuck. Longest chain rules.
FTFY
Satoshi knew that once he slipped that blocksize limit into the core client, it would be there forever, and become the de facto standard in all bitcoin software implementations. That's why Garzik and the others were opposed to it at the time. Satoshi said that it was temporary, but he knew enough about game theory to realize 1MB blocks would become a Schelling Point within the bitcoin network if it was left in the core client long enough.
That's simply not true. You're claiming to know the mind of Satoshi in direct opposition with his public statements.
https://bitcointalk.org/index.php?topic=1347.msg15139#msg15139Satoshi is dead. I dont give a fuck what he intended anymore.