IMHO all pilots should have 1500 hrs and an unfrozen ATPL before being allowed to sit as a 1st officer, in an airline.
Well come on lets be serious here. Where are you honestly going to get 500hrs Multi pilot time before gaining employment with an airline? I can imagine some have done it but they will be in the minority.
All experience is good, and all flying is real. Do your own thing and don't hate!
Peace.