Older C++ compilers couldn't distinguish between a right-shift operator and the closing of multiple template parameter lists, but few people figured out you just had to put spaces between all those >s.
In 2005, I didn't know anyone who could afford a copy of the specification. My point was that many of the other C++ programmers I knew at the time assumed it wasn't possible to nestedly use type parameters, so they just avoided it. I'm sure there were probably a cryptic error message and several toxic message board communities involved, too.
I think hardly any C++ programmers look at the actual specification even today. Once in a while someone will reference the draft specification immediately prior to the actual specification (because the draft is available for free). People mostly look at sites like stack overflow and cppreference.com , via Google. I don't know what the status of that type of documentation was in 2005.