Places like Murky, that take espresso serious and pour their hearts and souls into making perfect creations, knows that pouring shots of espresso over ice spells trouble for two main reasons:

First, the make-up of the shot itself goes through a slight change when abruptly introduced to ice--and the result downgrades a creamy and flavorful shot to a slightly bitter alter ego of a shot.

Second, as a former barrista, I know that 99% of the people who order espresso over ice are planning to create what industry folks call the "Ghetto Latte." Shots of espresso are much more cheap than iced lattes. . .and the Ghetto Latte connoisseur knows this. They get their espresso over ice, walk over to the sugar/cream bar, and fill their cup to the brim with milk and sugar. . .thus, getting out of the $1.00 or so extra that would cover the cost for that sugar and milk. Yes, that's right. . .these people are cheap bastiches.

I frequent places like Murky because they take espresso seriously and won't rape a shot no matter how much a cheap bastard will tip or feel good about himself. If you want a crap drink, that is what Starbucks is for.