I don't see how something such as this could become a habit - if you don't want to crack anymore, just simply don't push or pull on your fingers lol - seems like something easy enough to stop if I ever want to.
Clearly you have never tried or cracked long enough to know what it is like - but to the author of this thread - is it really worth it to start cracking?
To have a dependancy on releasing tension in your joints and being uncomfortable if you don't.
Take heed to Jointcracker's words.