That and the fact no one would observe the rule anyway.
There are a lot of ingredients that fuel successful agencies. Coffee. Creativity. Insight. Brains. Energy. Endurance. Optimism. Pessimism. Humor. The ever shifting line between art and commerce. Those innocent, wide-eyed, crazy bounders who believe against all evidence and reason what consumers are really looking for are more ways to engage with your client's brand.
But because of the nature of the beast—buildings loaded with egos, knit caps, planners, egos, man-buns, ironic t-shirts, skinny jeans, millennials, unrestrained enthusiasm, egos, people who know better, egos, people who enjoy inhaling their own fumes, egos and meetings, help me Jesus the meetings—agencies can't help but run on another more fragrant ingredient.
It is after all a sales job. And while there are good salespeople and bad ones, tolerable ones and insufferable ones, at the end of the day (EOTD = ad term, don't get me started) it all boils down to the size shovel they're using.
I know a lot of people in the business will call bullshit on this post.
But that's only because they didn't read the sign.