More has to do with mental pressure of scoring a target ...when batting first ,you are more free and you have option to defend a total by bowling and fielding even if you don’t bat too well ..there are no second chances while chasing...it’s like playing in second leg of football having lost first leg :)This was pretty much done as soon as India posted near 350.
Silly question but why is chasing a decent total in ODI where I don't think the wicket changes too much, so difficult?