The backlight does have a finite life (well, it'll just get dimmer - if you can imagine such a thing...). Hacking the kernel is a good way to kill the backlight if you don't want it on all the time when playing in the standard software. ISTR the half-life (ie, until half brightness) was in the thousands of hours.

Should be very simple to make it stay on for (say) 10 seconds after every key/IR press.

Hugo