Aiyo...Fai kor......your thread title sounds a little frightening......imo it's just human nature thing....we always try to find the shortest path for a routine...e.g. our daily walking path to MRT...despite there is a proper pathway....we still prefer to cut across the grass field because it's straight-line instead of the detour if we follow the fringe of the field
Similarly....all the existing maritime routes are discovered and refined over a long period of time, to be the most efficient and safe...as in this artic route....airline has done that long ago....it's only now that its feasible for shipping to negotiate this path due to subsided icy water.....but that is without its risks....imagine if the weather turn bad suddenly(typical for arctic or Antarctic weather).....or should a mishap happen like Titanic.....there will be a lot more Jack Dawson under the Baring Seas....of course this can be overcome by technology but that will add up to the business cost and adoption rate
Back to the subject, will this bad for Singapore? Definitely. Will it the end of the road for our port services? Definitely not, Singapore port's strength is it's transhipping hub status, ships docking here not only to unload but to top up their supply (cheap water, food and fuel) as well as cargos that brought in by other ships which go in the same direction...especially those super inter-ocean liner which don't call on many ports....they usually will stay by the most viable routes....that's why it's important our GIC own a part of these companies(not sure if they still do now) to have a say in this
As for the Kra-canal....like someone said before...the cost and benefit does not justify....also unlikely those big ships could afford to ignore a port that serves more than 300 million peoples in the southern hemisphere...so...I don't think this could happen in near future....