Gotta say I agree with most of what has been said.
This definitely shouldn't be taken as a dig at Indian students- there are a lot of very good students that I have had the pleasure of teaching over the years. These students are hard working, motivated and keen to learn. Unfortunately it's the younger and less mature students that usually struggle.
Often this is the first time these kids have been away from home after what has probably been a very sheltered life. So when they get here and are able to live away from the direct supervision from their parents, flying often takes a back seat to having fun.
Of course the schools will have no interest in trying to 'carry' them through their training (at least the good schools) and hence these students under achieve. And of course when questioned about the time taken and cost for their training the students will tell their parents a very different version of the truth which inevitably blames the school.
I hope these students will one day learn to take responsibiliity for their own shortcomings. It's all part of this 'someone else's fault' attitude that is so prevalent in this day and age. My 2c.