Security is always a tradeoff, and there are many usecases where a huge increase in security isn't worth even a tiny increase in accessibility or cost.
Let's take an example of cheap padlock on a garden shed or a lock on a filing cabinet. Both of them are trivially broken, either by skill or simply brute force. Yet, they achieve their security goal - they do prevent (as in, significantly reduce frequency) random passers-by from taking the stuff inside. A more secure model, such as smart cards, would be an inferior choice there due to increased cost and decreased usability.
For example, a secure system would require to make it harder for a random person to make copies of the key/token/whatever. An accessible system would require to actually make it easier - so that any keyholders can easily make copies without authorization from 'key owner' that takes some time and effort. For example, if a renter needs to involve the landlord to copy his key if one of them was lost, then it's more secure but less usable. "Easily copied" is a bug or a feature only depending on the system needs.
I just stayed at a hotel in New York with smart card locks. It was so nice to be able to just hold my wallet against the door rather than pull the card out of my wallet and try to remember which way the magstripe goes, etc.
The reader on the elevator was placed low enough that I just needed to stand within a few inches of it to "unlock" my floor.
It's 2014. Smart cards need to be everywhere. Even my college dorm had contactless smart card authentication.
Keys still have a place for manual override in outages, but that should be rare and set off alarms.