Here I must disagree. At TET the communists expected the ARVN to collapse and the population to rise up in support. Neither of which happened. They had localized victories - and there was heavy fighting in some areas especially Hue but it was a military disaster for the VC.
Had the press been reporting using the rules and standards of WW2 that might have been the end of it. BUT everyone was looking for a story - and 'American Embassy overrun' sells more papers than 'Attack on Embassy thwarted'
And yes it did not help that the American and ARVN forces ignored all the warning signs like the Allied command had done with the Battle of the Bulge in WW2. I think that is a good comparison - imagine if the start of that battle had been reported 'live' in the same way.....