I figure if you fly 20 to 30 hours and throw the sim away you are still ahead of the game.
Buy a 50 to 70 dollar game and play for 10 to 12 hours. Once you have defeated the game there is not much else to do.
I agree you can play the game again but there is not much new the second or third time through.
Flight Sim can probably be used for 10,000 hours and you would not have to ever fly the same route. Or you can fly the same route and use a different aircraft a lot of times before you have to change the route you fly.
There are still people flying FS2000 and earlier and still enjoying it.
Flight Sim is not for everyone but for those who like it is a lot of bang for your buck.