“The flag of traitors.”
Yes, the flag of people who thought for themselves, and resisted authority, as opposed to practicing obedience, compliance, and mindless conformity.
I’m not sure why you consider that to be a bad thing.
“The flag of losers.”
Yes, the flag of people that you oppressed and harmed. That flag of people that you actively inflicted pain on, using your power, strength, and wealth. The flag of people whose land you invaded. The flag of people whose rights you violated. The flag of people that you forced to remain part of the same country against their will.
I’m not sure how that makes those people and their flag bad, and you somehow good.
The fact that you would call the Confederates “traitors” and “losers,” as if these things are insults, means that you are a bully, a bigot, a conformist, and an authoritarian.
The fact that the Confederates “lost” does not reflect badly on them. It reflects badly on you.