Board Thread:General Discussion/@comment-4440927-20150410030856/@comment-34326521-20150419220159

"Arguments" against GT being canon range from things that the other two series have (often in greater amount, like plot inconsistencies), or plain fanaticism ("It wasn't made by Toriyama, so it's not canon!" - in fact, GT did have the help and approval of Toriyama; he even made a draft of a transformation).

It's amazing how similar the "arguments" used against Omniverse are, with plot inconsistencies being the main one.