AI is extremely popular option with the FA's at private airlines in India simply because it is a job for life with a LOT of perks such as subsidised accomadation, world wide travel and stays in 5* hotels during layovers.
Most aim for 3-5 years at IT, 9W, SG and 6E before heading towards the middle east or SQ but the key difference between AI and Middle East/SQ is that they have a contract for life whereas the others is fixed term appointments. In essence, AI does not trade them in for a younger, sexier model!
Don't forget, AI have the widest international coverage of all Indian airlines.