If miners get a high subsidy from coinbase transactions, fee markets might not really develop at these early stages, even in PoW coins.
Also you did not answer to the "not every coin needs to pay miners anyways" argument... Fees on Ripple for example are more fighting spam than helping in any measurable way to deflate the money issued.
I understand that subsidy keeps the fees low, but I am talking about the amount of money that people paid for using the network. Same with Ripple. XRP have value on the market, yet people are willing to spend them on transactions. The total amount of money that people are willing to spend using it, seems to me a very strong indicator of the true value that a payment network currently has.