It's not about "Fair", it's about "The Show". It's about one lane race tracks, with 140+ track temps, it's also about letting the 'little guys' getting into the "SHOW" on Saturday, because track temp is a great equalizer between the "Haves" and the "Have Nots".
I think about it as the "Route 66" Rule... and you can't change the 'rule' just because there may be a 'short field'... it happened when there were 22 to 24 cars showing up for each "PRO" class... and if you did not qualify in the 16 on Friday night under the lights, you didn't get in the field.
There is a way around it, Run Qualifying on both Friday and Saturday at 1 and 3 in the afternoon... opps, there goes your Friday Gate, can't have that.
d'kid