It isn't SO popular atm I supose. Older people have no clue what bitcoin is. I do think it would stay as "popular" as you think it is now though. I really can't give any reasons for this but it's just a feeling :-)
Even if its not popular to them, do you think that Bitcoin would be in any use for the elderly? Or will it make there life better or easier? I guess not because Bitcoin is designed for this generation in which are people who are technologically inclined that they can adapt easily compared to the elderly in which they would take much time to learm and understand Bitcoin. Additionally I think that they are better of using fiat currency in which is the most simple way to pay.