Because I didn't want to buy a new laptop for my wife.
The parts and tools from iFixit were perfect. The instructions were easy to follow and clear. Everything fit exactly as expected. The Mac charged the battery once after installing the new magsafe board and then, once again, flatlined. No complaints about the iFixit product or instructions. They were perfect, but the Mac in question is just, sadly, dead.
It might be nice to have a set of instructions for testing the suspect part with a multitester. I'm sure there is something else amiss with the mac (at this point I have replaced the battery and the charger and, now, the magsafe adapter board). If I could have tested the magsafe adapter board before replacing it I might have saved myself the cost of the part.