Flagburning? Why is everyone so disgusted with it?

I came across this lil fact today:

According to Title 4 of the U.S. Code:

"The flag, when it is in such condition that it is no longer a fitting emblem for display, should be destroyed in a dignified way, preferably by burning."

So, why is it that when someone burns a flag, people are so disgusted by it?
Don't they know their own laws and regulations or something?
Most flags I've seen burned on tele were dirty, torn, worn out or in a hostile environment where it would be unfitting for display.

Reference: Legal Information Institute

Because when you burn an old flag your intention is to burn it meaning no disrespect to your country. When your intent is to burn a perfectly good flag, clearly your motives are to make a derogatory statement about said flag and the country its from. "motive" Now this doesnt mean its ok to go gather old flags and have a bonfire.
I think you get the drift

Burning a damaged or outdated flag, if done properly, is actually a sign of respect since you don't just want to throw it away with the garbage. Burning a good flag in a protest while stomping on it and such is totally disrespectful to the country, and all the people who ever died for that flag.