Grumpy_Mike:
These techniques do assume that the switch has negligible resistance when it is closed.
Well no.
With a voltage required for a logic zero at 1.5V, and assuming the worst case (lowest ) pull up resistor of 30K, then your switch just has to have a resistance of 9K or less to register.
You say 'no', but we're saying the same thing. The comment of mine which you quoted was about the technique of combining a series resister with each switch and then reading overall resistance of a circuit that combines all the buttons into a single analog input - any significant variations in contact resistance could make that approach unworkable. I contrasted this with the straight forward one switch per input approach which, as you point out, is far less fussy about contact resistance.