Complex sentence: Firstly, because of an editorial and publishing trend, totally against Browne's artistic intentions, it was omitted from many Victorian editions, its "inexcusable Pythagorisme" little liked by the Victorians and thus it has been omitted from many modern editions.
Split into simpler sentences: Firstly, because of an editorial and publishing trend, totally against Browne's artistic intentions, it was omitted from many Victorian editions. Its "inexcusable Pythagorisme" was little liked by Victorian critics and thus it has been omitted from many modern editions.