A "license" is not a "grant" but a "restriction"
To put some perspective into this discussion, in the USA software 'sales' are controlled by our national Copyright laws. See: http://www.copyright.gov/title17/92chap5.html
Software sales could theoretically take place in the US without a 'license agreement' (EULA). However the common practice, supported by the US Universal Commercial Code (UCC) is that software companies create agreements (software licenses) that limit the rights of customers to a sub-set of the rights granted under our Copyright laws. Thus, a software license agreement can be viewed as a restriction of rights rather than a grant of rights. Customers agree to those rights in various ways during the purchase/installation process.
It would be quite possible to also sell a hacksaw under a license agreement if both parties - seller and purchaser - were amenable to such a business practice. After all, we already sell the right to use a car for a period of time under a license agreement.
But of course, no customers would agree to buy a hacksaw under a license agreement. And the obvious reason is that the cost of the hacksaw is pocket change.
However, a car often needs to be financed. It has a greater value. And that value drives the opportunity to 'sell' the use of the car under a license (a lease). The same is true about software. The intellectual property that gives the software its value is worth far more than anyone would be willing to pay for the use of the software, so the seller and the buyer agree to sell/purchase a limited right to use a copy of the software.
Microsoft has historically had less (or no) restriction on transferability of licenses, however their current Office agreements under Vista carry the following restriction:
The first user of the software may make a one time transfer of the software, and this agreement, directly to a third party. The first user must uninstall the software before transferring it separately from the device. The first user may not retain any copies.
and...
Before any permitted transfer, the other party must agree that this agreement applies to the transfer and use of the software. The transfer must include the proof of license.