Remember, this was all written before computer networking, let alone <i>inter</i>networking. The level of defensiveness required to write network-facing code wasn&#x27;t realised at the time.<p>The prevailing view of how to do things was based on tape (magnetic or paper). In that context, it&#x27;s really inconvenient to know how long your tape is before you write it and really convenient to just keep reading it until you hit a marker or the hardware says &quot;sorry, end of tape&quot;. See also the &quot;end of file&quot; character, ctrl-D.<p>Judging history in hindsight is uncharitable.