There are a couple of reasons why we need backed assets like OPENBTC and TRAD.BTC. The main reason in my mind is price-discovery. Other reasons also exist for these type of assets such as immediate liquidity can be offered by a market maker without entering into a short position, and exchanges can move their order books more easily to the DEX this way (and in a way that fits their existing business model). But I want to focus on the price-discovery issue here.
Instant gateways like blocktrades that offer BTC -> BTS need someway to figure out what price to offer. Right now, we use the prices on the centralized exchanges that support these pairs (and other indirect paths between these two coins). But we think it would be nice if such prices could be determined from the internal DEX as well. Now perhaps one could argue that we could just value 1 bitBTC as exactly 1 BTC. Then we could use pricing of BitBTC->BTS to price BTC->BTS. But while a BitBTC tends to be near in value to a BTC, it's generally not the same, so this becomes a somewhat tricky proposition. From our point of view, it's much easier to price against something that is worth exactly 1BTC to us, and TRADE.BTC fits this bill for us (OPENBTC would also work, since we could redeem it for a BTC).
These type of backed assets are particularly important when there is no corresponding asset being traded anywhere else yet (i.e not traded on a centralized exchange or the DEX). For example, we plan to offer TRADE.MUSE in a day or so, to enable people to buy/sell MUSE. In order for BlockTrades to offer BTS <-> MUSE instant pricing, we first need a market to be established between TRADE.MUSE and BTS on the DEX.
Also, since there seems to be some confusion about who owns what, I'd like to clarify that:
1) BlockTrades owns TRADE.xxx assets. We're mainly using them to test out the transaction software we've developed and we currently plan to keep them around as a backup if OPEN assets are temporarily inaccessible (this can happen if OpenLedger server loses internet service, has a wallet problem, or even just a computer dies).
2) OPEN assets are owned by OpenLedger (which is a CCEDK brand).
3) Cryptonomex is under contract to help CCEDK to get the OpenLedger service going and improve the service over time. I'm pretty sure Cryptonomex is willing to assist other exchanges to setup similar businesses. BlockTrades is too, for that matter, as we do contract work also.