I imagine it's a liquidity issue paired with some other random overhead costs.
Although like you said the overhead costs should be dirt cheap because they already list hive. at the end of the day HBD isn't actually needed for anything and demand is very low with a market cap of rank of #5000.
We need more dapps to utilize hbd to increase demand enough to get the listings.
Very chicken and egg scenario.
need liquidity to get liquidity
takes money to make money