I found this. 1st AC is having lowest loss. Though, you are partially right. I also stand corrected. But AC1/2 having some losses due to patronage/occupancy issue, free/confessional tickets instead of fare issue. Jitna AC Class ka loss hota hai use jyada ka neta log free mein 1st class travel kr lete hain.
IR rightly targetting major loss making classes.