They are wringing their hands because all these people will be retiring over the next few years, and there is no one in the wings to replace them.
It’s because the course of study is hard, the pay is not great, particularly once one gets past the 5 or 10 year mark, and at the slightest whiff of a downturn, you get laid off.
It doesn’t help that what once took 6 months (the P-80 shooting star), now takes 18 years or so (F-22), either.
These folks can do numbers, they know that they will be poorly paid, won’t have a secretary, and half-way through their careers, they may be asking, “Would you like fries with that”.
People don’t go into the field because it is an underpaid unattractive field.