[Patashu]

if you think about it, it's exponentially harder to get no goods than it is to get 1 good.

Imagine if you had a 1% chance of getting a good on any note and you played a 100 note song.
36.6% of the time you'd get no goods
37% of the time you'd get 1
18.5% of the time, 2
6.1% of the time, 3
1.5% of the time, 4
0.3% of the time, 5
etc
You can see that:
shaving one good off of a high number is a lot (exponentially!) easier than shaving one off a low number
and
at least for this case, you're more likely to get 1 good than none

you also have to consider the human factor; most people get nervous when they get close to an AAA they want, so it's actually better to be oblivious of the fact that you're getting good accuracy

edit: also, if one part of a song is abnormally harder than the rest to PA, you'll find that you might consistently get one or two goods while AAAing everything else. In Stepmania you'd tell if a song was like this because scores would have an abnormally high amount of greats relative to perfs relative to the number of notes total