Politics is such a complex topic and any simple representation of it will lead to what would appear to be contradictions in a person’s beliefs.
Absolutely. And certainly with this kind of geometric modelling, with a spectrum or plane where these broad and complex concepts are ordered more-than or less-than others.
The political compass is a better representation
I disagree with even this. It's not better, it's equally inappropriate.
The political compass is adding an extra idealist axis to an undefined axis (the linked video explains this in more proper detail). It's just digging further into a hole in an attempt to make it work, when the whole paradigm is wrong. And this is bad, because the compass model has rationalized that undefined, subjective linear spectrum. It helps delude people.
I believe that most of the things people do, or try to do, on reddit (and therefore reddit alternatives) just aren't appropriate for how the site is structured. Reddit is a 'link aggregator', that's what it was designed for. People post links to content.
So it's no surprise that forums are a better option, structurally, for a ton of communities.