My reasoning goes something like this.
"Top 40" bars that serve anyone anything anywhere anytime don't really develop
unique atmospheres of their own. They tend to get large crowds of indifferent
people who neither love the bar or hate it, but simply come for reasons like
convenience, or habit, or a good happy hour deal, and go just as easily. To
them it's "just a bar". If they were to move across town, or ran low on cash,
or even started making more money, they'd pick up and head out and you'd
probably never see them again.
Bars that cultivate regulars end up with groups of people who are passionately
for them and sometimes groups that are passionately against them. The one will
go to great lengths to go to that bar and possibly even that bar only, while
the other you couldn't drag in kicking and screaming. The clientelle ends up
being more compact, but is more stable.
Take the Village Idiot in New York, for example. It wasn't exactly an ordinary
bar, and some of the things they did could definitely be considered
intimidating, strange, or even offensive to some people. A bra collection was
displayed on top of the bar. Loud country music blared from the speakers. The
bartenders did shots with the customers, had been known to strain drinks with
their fingers, and danced with female patrons on top of the bar. When the
owner wasn't shotgunning beers to entertain the patrons he was busy arm
wrestling them for free pitchers or talking shit to them. It was an
anti-martini bar; I doubt they even had a bottle of vermouth, but certain
people loved it, and went to great lengths to go there, and there in
particular.
Or take the original Trader Vic's back in its heydey in Emeryville. It was
stuck off in the middle of Oakland, but because of the unique atmosphere
people would regularly do the trek across the bay just to go there, or
sometimes even fly in from out of state. You don't get that sort of dedication
from a bar that's exactly the same as every other bar; you get that from bars
that are unique. And part of being unique involves doing certain things
instead of others.
It's a tradeoff. Either you go for the larger fickle crowd that comes and goes
at whim and hope nobody builds a bar 3 feet closer with slightly cheaper
drinks, or you go for the smaller regular crowd that stays year after year,
and hope they don't get hit by cars or die of something. :)