If you own the hardware and you did not have to sign a contract to purchase it you're probably more than within your rights to modify the hardware to your liking (some exceptions to the rule do exist for things like circumventing copyright laws, modifying equipment to function in a manner harmful to others like operating a high energy transmitter in an emergency band etc).
What you're not getting when you hack your hardware to perform outside its bounds is the guarantee from the company. For example if you're sold a processor for $X dollars clocked at 2 GHz you're receiving an implicit guarantee that for Y years the product will be capable of performing every advertised combination of operations correctly. If you have a problem with this processor it is then reasonable for you to seek support for your problem/design etc. If you notice you can run this processor at 2.5GHz which would normally cost more money and for your application nothing appears to glitch you're welcome to do so. If you later encounter issues with occasional incorrect calculations you pretty much gave up the right to complain about that issue.
A similar example might be bolts for spacecraft. Many of the bolts for these spacecraft cost 100x more than the incredibly similar bolts one could obtain at a hardware store and often times may come from a very similar production line. The reason the spacecraft bolts cost more is because they've specified a very rigid set of minimum tolerances they require and stringent tracking requirements (if a bolt fails on one part of a spacecraft you may be able to get a list of every other bolt made in that lot, get the reference samples to test and find every individual location they were placed on that and other craft). It's not necessarily that the bolts cost substantially more to make but they do cost somewhat more to verify or select each piece from the line to meet the requirements. Even though hardware store customers might be able to buy bolts with spacecraft quality performance they just didn't pay to ALWAYS get bolts with spacecraft quality performance.
That said being a hardware person I'm not sure I feel the same way about software as many of the people here. It sort of feels like the primary argument is "hardware modification feels hard to me so its different". To me it seems like where it would be acceptable to modify a piece of hardware I own I should be able to open a debugger or disassembler and patch my software to enable any feature that's inherently part of the product (or new features if I wanted to add them). Now if that breaks updates, causes me to lose work or leads to problems I'd expect to be on my own like I would with hardware.
I'm sure my opinion isn't particularly popular, but changing a resistor and changing an if( premium ) to if( true ) just really don't seem all that different from where I am.