The difference between a pseudoscience and a far-fetched hypothesis is the attitude toward the scientific method. Wikipedia:

Pseudoscience is a claim, belief, or practice which is presented as scientific, but does not adhere to a valid scientific method, lacks supporting evidence or plausibility, cannot be reliably tested, or otherwise lacks scientific status.[1] Pseudoscience is often characterized by the use of vague, contradictory, exaggerated or unprovable claims, an over-reliance on confirmation rather than rigorous attempts at refutation, a lack of openness to evaluation by other experts, and a general absence of systematic processes to rationally develop theories.

In other words, using the popular map/territory meme, pseudoscience has no interest in making an accurate map, only a good-looking flashy one.