I guess you havent played during vanilla, perhaps i'm wrong but who knows you might not remember thigs like i do.
Repair now costs 50g when you die just repair!! I get from one garrison on average 500g daily with 20sec of time invested, do you know what you had to do and how much time you had to invest in order to get 500g in vanilla or TBC. If i remember right 600g was the price of epic ground skill, for most players that was a HUGE investment, i still remember seeing players without that while i used to do Wintergrasp during WotLK. Having 10k gold was a dream for most players in WotLK now you can earn that gold in <60min
Lets see, I have 13 characters on lvl 100 with full Garrison, inn, salvage yard ( i'm keeping chests and will open them if they introduce transmog bank or whats the name before legion ), that gives me about 6000g daily just from missions or 40K+ each week, i have 12 inscribers that are making cards and I flip 5000-7000 cards weekly, profit is 4g per card on a long run, so thats 20-28k each week from that, or 60k profit with 15min invested daily, thats 240k each month just from that.