When Kali-yuga is going to end only after 4,27,000 years, why do some devotees quote mundane prophecies about imminent world destruction?

From: Devdatt

H.H. Bhakti Tirtha Swami in his book Spiritiual Warrior part 3 “solace for the heart at difficult times says that there are many profecies about destruction of the world in near times. According to Mayain tradition the date predicted is 2012. Also there is book by ISKCON devotee Sahadev Prabhu “End of human civilisation”. However according to whater tiny knowledge I received from scriptures end of Kali- Yuga is going to be 4,27,000 years later then what is the basis of such predictions even by devotees?