Consider that recruiters also have to justify their own existence. From a business perspective, their position is a sunk cost. If they can't signal to their employer that their work is gaining the business something above and beyond just doing their day-to-day job then there's no chance of advancement.
They also dislike candidates that show proficiency in business for a few reasons.
First, the candidate is more likely to move on for a better opportunity.
Second, people with a business background like to 'shake things up' and head in new directions looking to maximize the potential of a company. Considering that HR's other primary responsibility is protecting the business from legal action, it's in their best interest to choose candidates who will stay on the straight and narrow and not shake things up.
Third, business types ignore the 'gatekeepers' and take action on their own. They may make a groundbreaking decision that takes the business in a new and more profitable direction. Unfortunately for HR, it's hard to ride on the back of an accomplishment that they weren't aware of to begin with. Worse yet, that same type of personality may have the potential to climb up the chain to a level where they're the boss of the HR person one day.
They aggressively select for 'code monkeys' because code monkeys do what their told, don't have enough soft skills to be a threat, suck at negotiation, and are too busy nerding out to look for something better.
