Many reasons. It is normalized. I remember a decade ago when taco bell advertised 24 hour drive through and made referencing to inventing yet another meal time to our arsenal. Social factors: People use food as tools of compliance, reject their food and they get offended. It gets even worse when they tie food to culture, then all of a sudden by eating responsibly you are genociding your heritage. We are in that smoking/drinking phase where we know the stuff ingested is poison and we do it anyway knowing full well of the ramifications. I would argue there is less urgency to call out this nonsense which is why people gleefully do it irrespective of the consequences. It is hard to call it out without being cancelled. Another big point I would make is people have no cause-and-effect understanding when it comes to the relationship between sugar and every problem it causes. They will decry their obesity, their lack of energy, their increased disease rate, their anxiety, their insomnia, their depression, while ignoring sugar as a possible culprit. Even looking at the DSM 5 for substance abuse shows significant overlaps with sugar addiction but people just cannot make the connection.