Additional point: the candidate may not be able to work (paid) at another company for a week without breaking part of their contract, such as a "devotion" clause.
(For example, something like a "the Employee must not, without the Company's prior written consent, engage in any other employment or business activity" line in the contract.)
That sir, is your opinion and has no bearing on the legal definition of good faith.
There is nothing inherently evil about exclusive employment agreements for full time employees and is fair to both parties.
In general though these kinds of restrictions tend to be upheld unless there is a state law against them. There have occasionally been proposals that a robust "right to work" law should generally protect the right to form new contracts selling one's labor to a willing buyer, and void any exclusivity contracts with other parties that would interfere with that right. But in practice all states that I know of with a "right to work" law have adopted a much more limited version of the right, which only voids very specific kinds of exclusivity contracts (relating to employer–union contracts). Some states separately void noncompete agreements under a related principle.
I'm not aware of any state voiding contracts relating to exclusive employment with the employer for the duration of the contract, at least for full-time, salaried employees.
[1] http://scholar.google.com/scholar_case?case=1733979708568541...
I say it probably does hold up because otherwise I am guessing they would have abandoned it. Microsoft has quite a bit of experience with labor dispute litigation. Having billions in cash is like chumming the water for labor law attorneys.
Reference: http://www.patentlyo.com/patent/2008/02/issues-with-emp.html