Yes. And when people say there is a shortage of food, they mean "at the price they are willing to pay". But new engineers and new foodstuffs will not spring into existence when you add a zero to the price - therefore there is a shortage. You might want to say but oh, more people will become engineers if salaries are higher! But that doesn't ship products this summer.

No, they mean there is a greater lack of engineers compared to other occupations requiring similar levels of education and therefore we should put more effort into educating and importing engineers. Saying we shouldn't focus on getting more engineers in those cases is just dumb, the economy would greatly benefit, you just want to protect your currently privileged position at the cost of society as a whole.