BBC micros in UK schools would be a good example of this kind of subsidy being beneficial.

It didn't matter that the chances of running into similar systems in industry were minute unless you ended up coding 6502 for factory automation. It gave a platform for children to experiment on and get used to the idea of coding.

Also, the percentage of children who this inspires doesn't even have to be particularly high for it to have definite beneficial economic effects further down the line and I would be amazed if this kind of effect would be measurable after less than 2 years.