My friend's parents were the same -- they did it on principle because the telco charged for touch tone. Never mind that it cost the telco substantially more to continue supporting the "rotary" infrastructure, I'm sure it was a cash cow.

I remember being awed by their new PC with its amazingly fast 9600 baud modem. And then it dialed out. ATDP. Tick. Tick tick tick. ....

I remember how it felt so high tech when putting in the number using beeppy buttons instead of the rotary dial !

My parents didn't get rid of theirs until about 5 or so years ago - I can't remember if it was because of the switch to a cell phone or their smaller house as they happened around the same time. I got to the point as a teenager that I tried to avoid using the phone to dial because it seemed so inconvenient.