I'm far from an expert, but as I understand it, the recommendation is to take advantage of what tax-advantaged account (401k, roth 401k, roth ira, traditional ira) that you have available.
Whether you do the traditional 401k or roth 401k has to do with whether you think you'll be in a higher tax rate now or later, but regardless of what you think you'll be in, having your money in taxable accounts is the least favorable choice.
Now as far as 401k up to the company match, the logic is that you don't want to leave free money on the table.
Then roth ira (5k) because of flexibility of investment choices.
Then the rest of the 401k (up to the legal limit of 17k this year) to max out your tax advantage account. If you're able to do this, you're putting away 22k a year toward retirement) that is tax advantaged.
I agree pretty much with Justus's explanation.
I would add to the "then roth ira" paragraph: the personal finance blogosphere has a(n arguably irrational) love for the Roth IRA. That's why it's second only to the theoretically instant 50-100% gain of an employer match.
Control and flexibility are nice, too. And most people who are considering maxing anything, and have a 401(k), are probably ineligible to contribute to a deferred traditional IRA. (A non-deferred TIRA is probably an option, but not a very good option.)
I would personally recommend a method that takes tax diversification into account, but then it wouldn't be a simple list as in the OP. The primary benefit of one size fits all rules of thumb is that they are simple to understand and implement.