Final answer:
People doubted Copernicus' heliocentric model because it conflicted with traditional philosophical beliefs backed by the Church and lacked empirical proof, with Aristotle's reasoning seen as more convincing. The complexity of the Ptolemaic system allowed it to persist, and fear of challenging established beliefs caused resistance to Copernicus' ideas, which persisted until Galileo provided supportive evidence.
Step-by-step explanation:
People doubted the conclusions of Copernicus because his heliocentric model contradicted the long-standing geocentric view supported by the philosophical tradition, which was backed by the Catholic Church. Experimentation wasn't highly regarded as proof during Copernicus' time, and the reasoning of Aristotle was considered more convincing without empirical evidence. Additionally, the Ptolemaic system, despite being complex, could still account for planetary motions, and the beautiful simplicity of Copernicus' system wasn't seen as enough evidence.
Despite Copernicus' inability to prove his theory empirically, it challenged the deep-seated belief systems of his time. This led to fear and anger among those who believed that such ideas threatened their worldview. It was not until Galileo's endorsement and evidence in support of the heliocentric view that it became difficult to deny, although he too faced great opposition and was punished by the Church for his advocacy of such "dangerous" opinions.