Instead of doing most shit in-house, they contracted out shit tons of parts to the lowest bidder

No that's not true. What happened is they found things that were not profitable to do in-house and sold those off (they found investors willing to take over their non-profitable production lines).

... the investors simply cut costs in order to make it profitable. Which is predictable, what else were they going to do? Obviously an investor expects to make money on their investment.

Now Boeing is basically stuck - they can't make the parts in house, because they don't have enough staff, and their only supplier sucks, and there is no other supplier.