I guess because for salaried people ITR may have non income such as stocks etc, which is not cash, so they might not accept ITR for Credit Limit Enhancement.
1. It's a bot reply.
Yes, it has other incomes which are not recurring, so to decide credit risk/paying capability they cannot them. To calculate the net worth these are useful but not for credit profiling.Isn't it good to consider other income for salaried people by asking them to provide ITR instead of just the recent salary slip?! Salary slip contains only the actual salary. ITR will have STCGT, LTCGT, etc. Those things would show a more realistic nature of one's credit profile.
That said... the recent layoffs in various industries and recent changes by RBI on risk weight are probable reasons for such measures. We can't change such policies.