I'm having the same issue. The keypad (smaller keypad that is battery powered) is impossible to see in a dimly lit area. The only key that illuminates onced touched is the unlock button. The numbers don't light up. Furthermore the green characters standing and walking, are so unbelievably hard to read in the dark that I'm amazed this got through a design process of professional security people.
What needs to happen is that once the armed entry is triggered, the keypad should illuminate all keys, so that the person entering can easily and confidently enter their code. My mother who is 75 is having a hard time seeing the pad in daytime and it's impossible for her without a flashlight in the evening.
Is it really expected that there be a flashlight handy for this? I doubt ADT or other alarms have this issue.