I agree terms "execute" and "rule" aren't precise.

I agree there are some people who most of the time do managerial job but still happen to code something from time to time.

I even agree there may be a few who are able to keep high standards on both paths. And this would be just an exception in a general rule.

Personally, I don't know anyone who excels both in management and in software development. I can say nothing about Scott Guthrie being a great manager. Actually the title doesn't tell anything about that.

Sure, there are people who are great managers and still write code. There are people who are great engineers and do some managerial job. I know examples of both. But in each case there's one single path which is main and another which is done mainly because it brings some fun or because it just happened so.

In almost every (if not every) case the secondary skill is, well, just secondary skill. Something you can be pretty fluent at, but far from level of people who do this all day long, 5 days a week, 50 weeks a year.

It's just mathematics. Consider a couple of similarly intelligent persons having comparable engineering skills. Now, one of them spends 8 hours a day at work coding and another couple at home hacking. Another one strives to keep average of 8 hours of coding per week. Let them work this way for a few years. Compare their engineering (and managerial) skills.

Are they still so similar?

If someone is able to keep ahead of the pack in both engineering and management this pretty much mean he's a kind of genius since he's able to spend way less time than anyone else to achieve the same results.

So I keep my point: in general "you can't do both" and be great at that.

If you're skilled or lucky you can be great at one and pretty fluent at another. "Pretty fluent" however is pretty far from true expertise.

Positive? :)

Also, I am not so sure I agree with the terms "execute" and "rule". Software Development is a craft where people come together and build stuff. People offer their best towards getting things done.

If getting impediments out of people’s way is what you are good at doesn’t mean you “rule”. It’s just another job.

Also, just because I am good at getting obstacles out of people’s way; doesn’t ‘always’ mean I just ‘cannot’ take up a small module couple and get better at writing code a couple of hours a day.

I love working with people. I manage multiple projects and write code for a module or two. I’ve seen a lot of other managers write code too without compromising their management responsibility. They do it because they love doing both.

Scott Guthrie is a classic example; A General Manager at Microsoft who leads ASP.NET development and writes code all the time on his blog. He also did basic implementations of Microsoft MVC.

It’s more of a personal preference than a rule. Suggesting that you ‘cannot’ do both seems like a generalization of a personal choice people make.