I don't agree to that either. Speaking of my roleplay e.g. i've opened a garage where i sell and tune cars from Japan or US.
I don't like the idea of everybody starting with 20k and getting money each week. It kills creativity, you can't be what you want. If someone wants to play a poor guy (well why not?) or a richer one, or a pilot or just a car enthusiast... anything you want you can't do it wit that defined amount of money.
And about realism... i didn't start my life with 20K and don't get 5K a week! I hope i could!