I feel its every bit as important for bitAssets to trade against other assets on external exchanges, as it is for BTSX to do so. Otherwise buying BTSX (soon BTS) is the only on-ramp to be able to get into bitAssets or buy bitUSD for trade. It adds another step, possible confusion and some risk in the process, when it should be as simple as possible.
BitUSD should not be removed from external exchanges for this reason but also that it would be a poor signal to outsiders. It is better to be be supported by arbitrage. If you stand in the BTER BitUSD/USD market to buy at $0.70 and get hit, then stand in the internal market to sell at $0.98 worth of BTSX and get hit on that, ship the BTSX back to BTER and sell it for a $0.28 profit. Now reality is you will pick up very little at $0.70, but you may pick up enough for this to be worthwhile at say $0.90. Incidentally tighter spreads improve liquidity, as we can see for NBT.
The real question is why are people not doing this and what can we do to support it. I think one issue is that people don't have an easy way to do such market making and arbitrage strategies. That's one reason why I came to thinking that a script/bot marketplace could be useful, as in my #7 post here...
https://bitsharestalk.org/index.php?topic=11004.0I think its only natural that if we claim the peg is working and outsiders see evidence that it is not, they will criticise. This isn't fair or unfair. It just tells us we need to get things working better and smarter.