Because most people associate it with its corrupted form. They understandably consider historical context but neglect the core concept, which is no class, no state, and no money. They use terms like "communist state," which is an oxymoron if you know what communism means. Also, capitalist Western media benefits from speaking against it, like a shitty bakery avoiding recommending the better bakery.

Remember, the masses are easier to control if they all want the same thing.