The reason I suggested you may be setting up a straw man is because the way you framed the argument is not how I’ve traditionally heard it framed (or framed it myself). Specifically, it’s not that coding + designing will limit your creativity, but that in the midst of a project, it could limit your output.
From your response above, it seems you agree: this can pose a real risk under certain circumstances.
Furthermore, I’ve never suggested that “code skill is a toxin,” nor have I really ever heard it framed that way. And anyone who does frame it that way is absolutely wrong. How can more knowledge ever be a bad thing? But knowledge and action are not necessarily the same thing.
But, overall it seems like we agree: the arguments that designers should or must do anything—design only, or design and code only—are both equally fallacious. And why wouldn’t we agree? You’re a designer who codes, and I’m a designer who used to code and who wants to understand the technical constraints as well as I can.
Now, if only I could be a virtuoso pianist, chef, programmer, designer, writer…I just need 72 hour days. :)