> I would wager that the issue with Marroco and in particular Turkey is more the lack of human rights, death penalty, corruption, weak democracy, unwillingness to acknowledge historic genocides, etc.
The entire idea has been deader than disco even on the Turkish side since Erdogan took power, but that was part of it, however I would turn your attention to former French President Nicolas Sarkozky’s comments on the matter: https://www.nytimes.com/2007/06/25/world/europe/25iht-union....
That said, you are also not wrong the issues around the Armenian Genocide were part of why member states campaigned against Turkish membership, as well as the issues around Cyprus and North Cyprus. The differences in law are less pressing though, and things you address during the negotiations for admission, but the process was halted long before it really got to that stage over political issues.
As for Morocco, the reason was much much simpler:
> The application was rejected on the grounds that Morocco was not considered to be a "European country" and hence could not join. This geographic membership criterion has been part of the EU's and its predecessors' treaties since the Treaty of Rome (Article 237 of the Treaty establishing the European Economic Community) and was later also included among the Copenhagen criteria. The rejection was expected as the King had sent feelers two years prior and received such a response.
So going back to your lead-in:
> Greenland has the option to join the EU. French Guiana is in south America and is part of the EU.
The EU has not made any of this black and white, but at least in the case of French Guiana, the fact that you are referring to it as a mere territory is reflective as to why it is complicated and negotiated through the core treaties that form the EU and the ascension treaties of new member states.
Greenland is part of the Kingdom of Denmark and its citizens are Danish and EU citizens, but the country itself actually voted to leave the European Union after it was afforded a higher degree of autonomy and self-government by the Kingdom. French Guiana on the other hand is an overseas département. It is physically located in South America, but its status as a département puts it legally on par with any département in France. It is considered as integral to the French Republic under French laws as Paris, and this applies to the other four overseas départements as well, but does not apply to all of France’s territories. For the Americans reading this thread, consider the detached nature of France’s overseas départements to be more similar in legal status to Hawaii or Alaska than to Puerto Rico or Guam.
The nature of these territories is also why Ceuta and Melilla are able to be admitted to the EU under Spanish sovereignty despite Morocco which wholly surrounds them being rejected and between the Danish, the French, the Dutch, the Spanish, the Portuguese, even Norway and formerly under the British when the UK was a member, there’s a lot of external territories that are or were considered part of the EU to varying degrees from wholly part of it to having no real part in it at all, although its people might still be considered EU citizens since they’re nationals and citizens of member states.