Even if communism, socialism, or whatever other economic model the left is pushing for worked, in its entirety, and made the world a better place
I'd still be against them wholeheartedly.
Because I no longer define leftists by their goals, but by what they are against.
They hate white men and straight people. They hate everything that isn't them, and they hate themselves.
They excuse hurting innocents, encourage authoritarianism and bigotry, and allow child abuse.
Their political and economic goals come second.
I'd still detest them because they are immoral, first and foremost.