What a shame. All the credit should go where its due. But why did the Burst and Qora developers not try to develop it for NXT which was the most popular Java based platform at the time it was invented? I believe NEM is also written in Java.
As far as I remember, the AT mechanism (the base for the Burst/Qora atomic swap technique) was indeed discussed to be added to NXT, but the NXT team decided to not include it because of possible dangers of turing-complete smart contracts. I think they could have added atomic swaps in a "hard-coded" way, but - for whatever reason - they didn't. That's one of the problems with those "centrally-developed coins" - if the "official" development team doesn't like an improvement, it won't happen.
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This is what makes me nervous about the whole 'core developer' idea ... actually I prefer to go through capitalism slavery rather than intellectual dictatorship

Anyway, done is done and most of the coins do not support AT inherently (actually a majority of coins even do not support CLTV, bitcoin before 0.11 for instance) but does it make cryptocurrency exchange world better if they would?
I appreciate guys discussing here and I found most of the posts very useful, Although I think we can go forward and ask whether implementing a full protocol in bitcoin and top altcoins to support atomic swap is a breakthrough in decentralized exchange development field?
It may look a trivial question with a big YES answer but I don't think so.