Even forgetting the illegality of the referendum and that it was done under occupation -- the results of the so-called referendum were completely falsified. See e.g. here https://kireev.livejournal.com/1095568.html (in russian, from a person who professionally analyzes elections) And personally I do think that it is possible that the majority of people in Crimea did want to join Russia, however we'll never know, because nobody cared to find out.