TL;DR Developers don't like it when marketing attempts to do their job. They like it even less when they have to clean up the mess when they fuck things up.

Our marketing team was specifically told not to put JS into the CMS. They were told that if you need JS for something, we will do it and then work it into a release. That wasn't good enough so they hired a design firm to "hack" the JS inline. They found a back door to get the JS in place but couldn't get it to work right. They called me to come look at it. After 5 minutes of explaining why they shouldn't have done what they did, I grudgingly decided to look at the JS. 30 seconds later I fixed what they had been screwing with for about 8 hours. They were using --> arrows in their comments! Seriously?!? designer != developer