In alternatives, maybe you should create a "easy" mode (jnano?) where there is all the nice feature for new user, and have a classic for old time user. Thanks.
I agree that this change is confusing for old user, and quite dangerous. Please revert it. Quit was for exiting without saving, the default behaviour should be to not save changes. IHMO changing ^K^X behaviour would be safer, or adding a new command. Don't understimate the muscle memory of users ...