In a word, no. Microsoft could not change the protocol because it still had to support the hundreds of millions of Microsoft Windows clients out in the field.

In a word, no. Microsoft could not change the protocol because it still had to support the hundreds of millions of Microsoft Windows clients out in the field. With Vista, Microsoft cleaned up the protocol a bit (SMB2), but it was the Samba team's paranoid fantasy that this somehow applied to them. Really, it was a long-overdue revision which helped performance tremendously. While the Samba team had a huge task, this does not excuse the extremely crappy implementation over the years: corrupt TDBs, lack of change notify, no native ACL support, oplock crashes due to the non-asynchronous, single threaded nature of each smbd, horrible Winbind scalability problems, domain join bugs, no real named pipe abstraction layer, no alternate data stream support, etc. And the code is just horrible to look at.