some context. Joe Montana is a legend at ND because he: (1) won a NC; (2) was a gritty gutsy QB; (3) consistently orchestrated comebacks just like the UH one.
The fact that this particular game underwhelms you is not surprising if you're just going to view the game in a vacuum without any context.
It is mythical because it's an exemplar game-outcome of Joe Mother Fucking Montana. Guy is deathly sick with flu, team is playing bad; Montana gets some soup and the team comes back from 22 down, with the key throw in the last minute.
Despite your review of the tape, the game will appropriately hold its rightful place in ND lore.