This strategy would quickly lose its merit outside of Harvard. Failing to gain tenure at Harvard is the expected outcome, so a) the sense of rejection is less, and b) your remaining job prospects are good because this is generally recognized (and it's Harvard).
Asking somebody at a high-tenure-rate, second-tier school to treat their tenure track position as an extended post-doc is essentially asking them to have a failed career, on the other hand.
(it's worth noting that Harvard has actually changed tack recently, such that they're increasingly promoting junior faculty...the above is still true regardless, at least for the time being)
This isn't true in computer science at Harvard - I speak from experience, having gone through the tenure process there myself. Being denied tenure in CS at Harvard is about as bad as being denied tenure anywhere else; people don't usually end up in very good jobs afterwards. In my 8 years at Harvard, we awarded tenure to 5 junior faculty, and denied tenure to two.
From an undergraduate standpoint, there certainly isn't a lack of interest in the program - the intro CS course is consistently one of the largest undergraduate courses. Though the smaller department size means certain courses aren't always offered, the quality of instruction tends to make up for this (as well as the possibility of cross-registering at MIT). A side effect of CS being an up-and-coming department is that many CS undergrads come to Harvard intending to study something else (say math, physics, or economics) and thus bring with them their diverse interests and skills to the classroom.
This isn't really a problem because Harvard and MIT allow students to cross-register (for up to half of your credits, the same as if you transferred from another school, although I'm not sure if the rules have changed in recent years).
It would seem like anyone worth their salt in computer science could get a corporate job after 7 years at any school, especially Harvard. It seems like the concept of having a failed career is much less than if the Phd was in Philosophy.
I honestly don't know what the job market is like for a CS PhD, so I can't rebut this statement. On the other hand, we interview a lot of PhD.s, and by and large they have little clue about how to provide value. They want to sketch out ideas in Matlab, and throw it over the wall to a bunch of programmers (which in the academic world are postdocs and grad students) to deal with the "implementation details". Many can't write a simple for loop.
That's sweeping, overstated, and unfair of me, but the job skills are quite different. Applied, directed research aimed at producing tangible and sell-able results is very hard, and by-and-large not what they do, at least based on who applies and interviews (which is of course a terribly biased and perhaps non-representative selection).
Based on personal experience (small sample size), Phds in Computer Science can find homes at consulting firms (hired for "being smart"), and software and hardware firms that utilize their speciality, and even hedge funds. It can be hard to unlearn habits over 6 or 7 years, but I've seen it happen.
The real point though is it's a lot easier than many other fields.
I more or less endorse the article. Seven years is a lot of time. I'd only give someone new a little bit of advice.
(1) Do a good job of your teaching, but economize on the effort you put into it.
(2) Be civil to everyone, from the department head on down to the janitor.
(3) Do your service/committee work as asked, and do it cheerfully, but for the most part don't go the extra mile. (And when you do go the extra mile, do so because you believe it's important, not because you believe it will win you brownie points.)
But above all:
(4) Kick ass in your scholarship.
There are plenty of sources that purport to break down and explain (4), some of which are worth reading, especially if caught in a rut -- but if you are successfully kicking ass, and paying at least minimal attention to career advice when it comes your way -- then I'd only worry about continuing to kick ass.
Asking somebody at a high-tenure-rate, second-tier school to treat their tenure track position as an extended post-doc is essentially asking them to have a failed career, on the other hand.
(it's worth noting that Harvard has actually changed tack recently, such that they're increasingly promoting junior faculty...the above is still true regardless, at least for the time being)