I think Tynon's point is to use gems to accelerate. the gains (massive gains I might add) in HP is tremendous. Thus the gem prices to accelerate.
If everyone can get to lvl 10 then everyone would have significant powers making beating Heroics and Royal challenge a bit too easy.
I would however agree, that 5 feeding is a bit too low.
I would opt for 10x feeding per day.
Or remove the cap and have the coins needed accelerate to be commensurate to the cost to buy the coins with 15 gems = 200 XP.
EDIT:
Also amount of feed times to go up with level makes sense too since the mounts get bigger ... thus needing more food 