2. There's nothing inherently wrong with being a Marxist (despite an obvious misunderstanding of economics).
3. From 1 and 2, it is only your politically correct / conversationally damaging standoffishness that creates your perception of "heated". This explains a lot really. You're more worried about being inoffensive than right, which is exactly why you've chosen the path you've chosen. Ignoring facts and complaining about nonexistent "strong and heated" words. This isn't a good way to learn anything.