I disagree.

With abstraction changes due for Metropolis, miners do not need ETH gas to accept transactions.

Miners can accept transactions for an app that does not charge fees. The fees can be routed back to the app developers or to another entity. They might need to be incentivized in other ways (different token, devs mining themselves, paying miners etc.) but that doesn't matter. You do have to pay for the blockchain somehow. Ethereum will allow miners and developers to be very flexible with how their application runs.

This is very much an acceptable tradeoff IMO.