Part of the issue is inter-team communication and part of the problem comes from that very phrase "dumbing down". I often hear people argue for "dumbing things down" when there is an overwhelming amount of information, but that phrase:

1. Treats people's intelligence as 1-dimensional, which it is not.

2. Gives no clear direction to an engineer who is passionate about UX, recognises that humans are multidimensional, and is trying to ask about what their users really need.

You might say I'm arguing semantics, but communication matters!

Without it, you can write code at high speed, but you won't learn what direction to go in order to present information appropriately and contextually to create a rich but easy, intuitive flow.