During his lifetime in the 19th century Papoulakos was a controversial figure and was persecuted and misunderstood by the Church of Greece which he faithfully served. Sadly there are still some clergy today who maintain that Papoulakos is still a controversial figure who should not be as honored as he is. An excellent 13-page defense of Papoulakos was written by Metropolitan Epiphanios of Thera which fully justifies the sanctity of Papoulakos and why he is worthy of honor.
The full text of this text in Greek can be read here and here (pdf).
To read more about Papoulakos, see here.