Stacked to a casual = how many celebrity fighters do I recognize?
Stacked to more invested fans = techniques, records, styles, result outcomes, pre-ufc careers for unknown fighters, who's reffing, who's commentating, learning and analyzing + heaps of other stuff.
I get it, on paper a 'stacked' card has more appeal, but if you don't know who's fighting take a moment to look them up and you may enjoy 'non-stacked' cards more.