Generally speaking, I don't think it is a good idea to subsidize fees for exchanges to pay for exchange listings, but like my stance on the proposal in question, I'm not really arguing that it is some form of moral imperative to avoid doing so.

In the case of exchanges, I just don't think it makes sense to pay for listings normally, because if the exchange doesn't profit from the market in the long run, it will just drop the listing anyways. So, in that case, paying for a listing mostly makes sense if your intent is to capitalize on the short term bump in price when the coin gets initially listed on a big exchange. And my perhaps cynical view is that is why some token projects buy their listings.

Now with all that said, I think there can be a legitimate case made for getting more exposure for a token by getting listed on exchanges. But so far, there hasn't been a case where it seemed to make sense for Hive to pay to get listed on an exchange.

Similarly here, I think if we're going to setup an AMM, I think it should be designed so that its economics make it self-sufficient.

AFAIK Hive-engine has set up some AMMs already but I haven't investigated them yet (I think they're called Diesel pools). And I suspect we'll see some operating on the SQL smart contract processing platform that we'll be developing next as well. And I don't think it would be that much trouble for someone to code one up on the 1st layer between Hive and HBD, if there seems to be sufficient interest in that.