Then the "boutique" ops aren't running two trips a day from the same boat, end of story.
It's called quality vs. quantity and customer service - which means not rushing the morning divers because we have a schedule to keep.
True, it's difficult for those of us who run boutique shops to run a "true" 2-tank afternoon dive in the winter months due to the early night fall - but we routinely do a two-tank twilight/night dive, departing at 3:00 or 4:00ish during the winter. During the summer, it's easy to get a quality afternoon trip in without rushing the morning divers back. We depart between 2:00 and 2:30 in the summer months for an afternoon set of dives.
We most often get more quality bottom time in two dives than many get in 3 or 4 dives with the less expensive operations even with the AL 80's - a good DM knows how to plan the dive and profile to maximize quality bottom time.
As is always said - it's a matter of personal preference.