The A-Bomb and synthetic penicillin were attractive war weapons, not because they were easy - but because they were hard

Shades of President Kennedy explaining his decision to push for an all-out effort to land men on the Moon before the end of the decade, "not because it was easy but because it was hard" !

"Hard" attracted lots of top (alpha male) scientists who could graceful forget about doing something boringly useful in this current war by focusing instead on daydreams of achieving eternal scientific glory.

The glory of building a new bomb that would fire-bomb entire cities just as good as existing fire bombs already were  and the glory of artificially synthesizing an already existing - and already useful- natural substance.

"Hard" also meant that A-Bombs and synthetic penicillin would remain a dark secret to the enemy for at least a year or three, even after their first use at the front revealed their existence : this is the reason why the OSRD and their British equivalent were so interested in these "hard" projects....