The number of people who are super talented engineers AND who will work for what I will pay them in the USA is far too low.

ftfy

Maybe I'm being cynical, but I don't know how else to translate "super motivated" from corpspeak.

More context is revealed in his followup tweet:

Humans can be thought of as hardware (inherent talent) and software (education & training). Even if someone has a strong brain/hardware, if their training/software is bad, that can be very hard to reverse. As the saying goes, it is hard to teach old dogs new tricks.

This is in reply to someone asking if he can rehire Boeing engineers. The implication here is that he wants young less experienced graduates who can be molded under his vision and direction, and who won't have a lot of baked in demands like high salary or time off to spend with their families. Many replies after that point out how new engineering graduates in America are having a hard time finding work, and he doesn't have a response for those.