Considering how long English has been mandatory and what the average level of English proficiency actually is, it might be a little too early to be overly optimistic. The potential is there, but it will depend mostly on the execution and based on current experience I wouldn't expect too much.
Demand wouldn't decrease because of more developers being on the market. Supply would increase. Just because any one developer might be individually in less demand doesn't mean that demand for developers has decreased. Yes, this would still depress salaries for developers.
Having said that, there is no fixed amount demand for developers. If development resources are a bottleneck for development projects moving forward, there being more developers may actually increase demand. This comes about as projects that otherwise wouldn't be started do get started and may, themselves, not be able to be fully staffed even with the new blood. I don't know that this would actually happen... but then again I suspect the Japanese don't really know what will happen either.
You can't just look at the two values of current demand and current supply and extrapolate that into a vision of the future... there are many, many more variables than that.
Interesting. The situation when robots not only take the people jobs but because of the robots new jobs get created, comes to mind. Isn't it similar to that?
Yet, I think that robots don't create as many jobs as they take.
There wouldn't be less demand, there would be a higher supply.
In any case IoT is doing it's best to massively increase demand for programmers. Once everything is sufficiently IoTified programming will be as common a tool as a hammer.
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