I don’t think this is entirely accurate. The Church Fathers did not read Plato as if they were reading Holy Scripture. Far from it. They took from Plato what could be in accord with Holy Scripture and the catholic faith and left out what was not or changed the meaning of it. Various heresies that surfaced they wrote against such as a dual principle of creation, good and evil, or God and an evil principle such as matter or bodies, cf. manichaeism. The orthodox fathers knew the error of this and wrote against it as early as St Irenaeus I believe if not earlier. The Fathers taught and believed that God created the world out of nothing and that it was good including matter as Genesis 1 says a number of times and concluding with “God saw everything he had made and it was very good”. There were some aberrations among a few of the fathers such as Origen who allowed his Platonism to influence some unorthodox teachings of his but which were not yet defined by the Church. That said, Origin was one of the greatest christian scholars and theologians of his time.
The idea in a certain sense of ‘despising’ the flesh and the body was more about sin and christian asceticism, taming the desires of the flesh, concupiscience, original sin, and growth in holines. St Paul himself says ‘I see another law in my members’ and ‘the flesh lusted against the spirit and the spirit against the flesh’. It was not that our very bodies, flesh, or matter were evil, this was heretical and were heresies. Jesus himself said ‘He who does not deny himself and take up his cross and follow me cannot be my disciple’. Christian asceticism is a necessary component of the christian spiritual life, growth in holiness, and the following of Christ.