If there should be such a thing as inspiration, 'to paint the town red' - literally! the betel-nut-chewing, and red-lime-spitting Bhutanese citizenry should stand out as sample numero uno, in a class that is all apart and on its own.
Proof of statement:

And so, they stand... highly conspicuous and, very noticeably arranged in an inglorious collage of red and white lime-smears.

Regular and everyday members of this Doma-eating clan go on to even attribute these behavior as part of the great Bhutanese philosophy of Gross National Happiness (GNH).
Well, can't say much on 'national' or 'happiness' but state-of-affairs are sure very gross in this matter. In fact undeniably and downright gross.
A logically-derived explanation among these clansmen and women, it goes like this:
"Culture is one of the main elements of GNH, eating Doma and offering it to people is part of the culture."
This bit is true... it is, customary practice and a Bhutanese tradition of old etc.
The righteous expression is however subject to behavioral patterns of every human mind, that take after individual grooming patterns, incidents witnessed, moral lessons learned through small or long time-periods under individual capacity of intellect and discretion.
Anyway, and regardless of longstanding civic laws or general civilized conduct, it is the express belief among the many avatars of doma eaters that spitting comes from eating, same goes for smearing lime on flagpoles, walls, windows, trash bins, electric poles, circuit boxes and every other visible structure.
And yes, all this traces back to culture for them (hyperbole).
Well, if logic was the only thing to be considered, the argument pretty much stands the grounds for all kinds of kudos.
But it is unfortunately NOT (thank god!)
Oh! and how can you forget the divine side of explanations to this glorious indulgence of things.

It goes something like this:

Tall tales??? Believe it, not believe it, believe it anyway...
But you must agree,... they sure make for brilliant conversation spice. What counts (seemingly) is, so long as mouths are red, streets are white&red and business is good, Doma all the way!!!.