The shower didn't drain, the sink was slow to drain and the wifi was hit and miss! Your in Greece, sorry the biggest issue here is your expectations!
Also while your Gold that does not really get you much at this property and you were offered a room change which solved your issues and by the sounds of it was still within the category you booked just not to your liking, so the hotel did try and address the issues you just didn't like it!
You were then offered a suite the next day when others became available and you went on to post a tripadvisor review before you had even finished your stay to see if they could recover the situation despite much of the situation being your expectations!
Have to say I can see where the hotel owner was coming from it seems very clear that there was no way you would ever be satisfied and most probably taken up so much of the staffs time and if these complaints were all being done in public probably also upset other guests! When trying to get things resolved it is pointless having unrealistic expectations and also showing someone that no matter what they do you will not be happy, otherwise they would give up!
As for choosing to leave Greece because you didn't like one hotel, that seems to say far more about your attitude than the hotel.