Let see the past where India lost in t20 world cup maybe due to IPL
2009- Due to general assembly election whole Ipl shifted to South Africa. Ipl ended on 24th may. World cup started on 5th june. Due to excessive journey Players were tired and India lost all 3 super 8 match. Coach Gary kirsten directly put allegation on ipl for this.
2010- IPl were scheduled from 12th march to 25 april. Then india went to west indies for world cup. And lost all matches in group 8.
2012- this time scenario was little different. Almost after 2 month of IPL , World cup started in srilanka. But india lost in super 8 due to low run rate. And that was rumoured that Indian player didn't give much effort in worldcup as they gave during IPL.
It's not the first time that India are out of a global tournament before the last four stage but never has it been so frustrating where one could clearly read the writing on the wall.