Higher loan rates on polo are generally a bad thing. The higher the loan rate the more demand for shorting the currency there is as the market expects the price to drop.
The only high loan rate on polo that is good is BTC, because all of the margin accounts run on using BTC to buy other currencies expecting them to go up, not necessarily for BTC to go down.
RE: Bitshares Is Lending At A Rate Of Over 1.9% On Poloniex's Lending Market Right Now!