I recently started a marketing consulting company, and boy, is it growing. I am in a position where I am going to start scaling. I get frustrated because some of my clients need technical things done that I can't do. I am exceptional on the business/client development/marketing/results side, and I am maxed out, working 16 hour days to support the growth I'm dealing with. Is it a waste of time for me to learn to code, or will learning this skill still add value?
No. You're too busy doing what it sounds like you are already very competent at. I think that if you work closely with great engineering talent, you will increase your overall product sensibilities.
I think that the "learn to code" movement has become over marketed and is starting to take a "7 minute abs" absurdity. While I have no doubt that it's producing people who are able to have some understanding of the languages, it's not the same as being an experienced problem-solver.
Furthermore, given the rapidly changing nature of things, maintaining a competency in programming requires a constant learning cycle, one that will inevitably compete with your core competencies.
Also, your reputation might suffer if instead of sourcing as you currently do, you take on these initiatives and execute at a lower degree of quality.