It’s a symbol. A symbol can mean different things to different people and illicit different responses. Context can also play an important role. Everyone has something in their lives that have personal meaning and illicit reverence, disgust, and every emotion in between. Each response is valid for that person. I personally would never burn an American flag, but I support others to have that right.
It is tribalism to a degree, but it can go much, much deeper than that. You’re right, its just a bit of cloth, but a dead body is just a blob of organic matter. Yet we generally show a lot of reverence for them. If it is someone you knew and were close to, you may have a problem with someone mutilating said body. Or if you are a doctor harvesting an organ, you are saving a life. Or if it is the body of a despot dictator you may have mixed feelings about it - or even out right glee.
Your opinion of the flag is valid, and so is mine, and so is anyone else’s.
