Personally, if I eat breakfast, I have to eat a protein-focused breakfast. If I eat a carb-focused or carb-exclusive breakfast (like Cheerios), I am unsatisfied and end up eating poorly (and more carb-focused) for the rest of the day.
But, to each his/her own
. Cheerios is high in nutrients so I don't really think you could call it a "bad" breakfast choice. Just as long as it fits into an overall diet of healthy fruits, vegetables, fat, and protein throughout the rest of the day.