As was stated earlier,
Rather a simplistic view of history omitting lots of facts and interjecting a political bias. One in particular was a sovereign country (Texas), so why isn't it flown equally as well as the flags of the indigenous populations ?
Under the Articles of Confederation adopted in 1781, and the United States Constitution, ratified in 1789 . This union was widely understood by both the states and the federal government to be voluntary, and the Constitution was interpreted to reinforce this perspective. At the same time, the founding fathers, particularly Thomas Jefferson, recognized the states' right to secede. This I point out as your pejorative claim of "traitors" is baseless as the states were acting under the agreements as interpreted by the founders.
The current politically correctness (PC) fervor that's the popular rage attempts to silence everyone. There's not as a right to not be offended.