When I placed my vote I didn't understand that you were referring to re-enabling disabled/downgraded functions. What I was thinking about was more tweaking in the sense of adding own functionality to a product which I have purchased, e.g. adding a wireless transmitter to an electronic bathroom scale (a project on my long to-do list), building current amplifier front-ends for DMMs, but also connecting the "forgotten" serial connector on a handheld GPS etc.
Of course I understand the fact that today the value of the hardware itself is often little as compared to the firmware development cost, and thus companies may choose to cripple certain functions and sell the downgraded product for a lower price - actually: why? The company would not loose anything by shipping out the full version, because the firmware development cost has already been spent.
When it comes to software on the other hand, the crippled versions are often a limitation for the user to make profit from the software, e.g. the freeware version of Cadsoft Eagle. Obviously you get the full program code when downloading the software, but with the limitations of the freeware version - even if you wanted - you will hardly be able to develop profitable products. I find that fair, would even be willing to pay for a - for me - reasonably featured version of the software.