We fell for two reasons. The immediate cause is an excessive tilt towards Mayavada (Illusionism) under the influence of Buddha and Shankara. I am not saying these great Masters were all about Illusionism but that is how their message came across. We abandoned the Yoga of Sri Rama, Janaka, Sri Krishna, Arjuna in favour of an otherworldly asceticism considering the ochre robe and the world shunning saint as the hallmark of spiritual life. This misunderstanding still persists with individual moksha as the highest goal and hence the life energy is yet not fully creative.
The second reason is the excessive importance to karmakand, to bahya pooja, various rituals to appease the grahas etc giving us partly a sense of false security and, secondly looking always outside for help, in the priest or the gods rather than seeking the strength of the soul and of God within.
Of course in a way, it was all Willed because the Age was changing and the evolutionary energy in the race was working on matter for which the Western world was to be the stage. But now the cycle is complete and India will rise again but on a new and higher spiritual basis.
Affectionately,
Alok Da