This is how the phrase talk is cheap came to be.
Giving your word or even casually just saying thing you do not have the intention to follow through is just not how you should live.
I had a room mate once and she used to just say every time there was some little mess or some little issue in the house "well today I am going to clean this up" or "today I am going to dust the rugs" but even after a week nothing was done ever and no one even bothered to ask her why, because everyone knew that this is just cheap talk.
So not only in the important matters, even the slightest little thing in one's life, one should always only utter words carefully.