[LunaSea]

Few reasons, one of them is that the Maginot line was built during a time where France was an industrial powerhouse. This has not been the case in a long time.

The other point, is that you are comparing a public infrastructure project with a private company.

Said private company behaves like one and does not want to take unnecessary risks by recruiting and training too much staff and later not having enough orders to keep them on the payroll.

[swores]

Minor pedantic FYI - although your comment was clear (I think, or maybe I did misunderstand it), there's a linguistic difference between "Few reasons" (meaning "there aren't many reasons) and "A few reasons" (meaning "more than one", but implying that you're introducing the reasons, not that you're quantifying them as not many).