Even before we started coding, there was an RFC written by us. We have talked about it, discussed it, ironed it out with the chief architects of the project. When everything made sense we started implementing it. Total coding hours is irrelevant, but it's small when compared all the planning and it's almost finished now.
The code needs to tap and fit into a specific place in the pipeline. Finding and communicating this place was crucial. The code is not. Because you can write the most sophisticated code in the most elegant way, but if you don't design and implement it to fit to the correct place, that code is toast, and the effort is a waste.
So yes, code might be the most enjoyable (and sometimes voluminous) part, but it's 5% of the job, by weight, at most.
These are all engineering tasks, and the longer you spend on a team/in a company, the more likely it is you provide more value by doing this than by slinging code. You become a repository of institutional knowledge to dispense.
If you can communicate it can be 99% of the value. Getting someone to write something to back it up is trivial in comparison.
"Talk is cheap. Show me the code."
- Linus TorvaldsAll the while: You are correct, being able to produce anything that solves a problem is much more valuable than being able to talk about it. But in order to unlock the value (beyond solving your own problem) absolutely requires communication
I have written plenty of code that's stuck on this first step in my life, including some that went to the very same LKML we're talking about here right now. Some of those things have already been independently written again by other people who actually managed to go further than that.