Sometimes, bad habits are not seen by the individual as bad. They just think it's all about what others feel about them.
It's a wise deposition to control ourselves - character and emotion wise. Learning discipline is good.
Ability to trim our excesses and eliminate bad habits from us is a proof that we have feelings for others.
Discipline is something most people don't really know how to apply, certainly when it comes to behaviours they see as enjoyable even those those behaviours may be detrimental to them.