Senior programming "guru" who can't program - should I find a different career?

I don't really see anything about this that suggests he can't actually program. The worst bit might be this:

"... if you ask me to sit down and code up a new application from scratch I will spend ten times longer than programmers who are much more junior than me."

That doesn't sound so bad to me. It kind of implies that he can still get the job done, just more slowly than some others. I don't know if that should be a "I can't program" qualifier, though.

He must not think that his extra coding time adds any value to the process. In my case, I know I'm not always the fastest around, but I like to think that my code is better designed and easier to maintain than the average (* may or may not be true...) because I'm almost pathological about building my applications from small, self-contained components, never having the same logic exist in more than one place if at all possible, and perhaps most importantly, clean, clear and consistent naming conventions. That kind of stuff takes time but, IMO, improves overall quality in immeasurable ways. Speed isn't everything.

It's always nice to see someone do an honest self assessment, and then own up to it, even the negative parts. My current office-mate is like this, he sucks at coding, but is very broadly knowledgable in tech stuff, and very good at bringing ideas together, and getting broad strokes of what needs to be done fleshed out. I'm sure a lot of places will hire someone like this, but the job title is usually Architect or similar.

As a tangent, if I was him, I would fess up to this at interview time -- any employer who doesn't want good self assessment from employees doesn't deserve someone like this.

I think I've worked with you before.