I agree this is a problem for almost every team that travels to other countries, they don't seem to adapt to the conditions and most times lose the series. The only team that was a great team at travelling was the Australian team of the 90's and early 2000's This team would win series everywhere it went even won a test series in India, in my opinion that was the best cricket team of all time as it was well balanced with good batsman that could play on most pitches and a good mix of bowlers. Not sure if we will ever see a team like this again.
Other teams also struggle on unfamiliar conditions, but being regarded as the sole cricketing super-power, the Indians were supposed to fare better. After all, their players receive 10x salaries when compared to the Australian and the British players.
There is no doubt regarding the bad performance by the Indian players, they have played really bad cricket which was not expected. I think Indian batsman should play more aggressively and should counter attack the bowlers, if they managed to get few runs then it will boost their confidence. Too much defense is freezing the flow of the runs and increasing the risk of loosing wickets.