"...but have you considered my new and totally original strategy of blowing up more civilians, then progressing the war from strategic bombing to simply making the rubble bounce with high explosive until the enemy is so impressed that they throw in the towel." - Air Marshal Sir Horatio Windbag-Tollemache-Tollemache-Blimp, career office officer.
Like other commentators above, you are missing a VERY real point.
In the 1920s and 30s, the public WAS afraid of aircraft carrying explosive bombs but MORE afraid of those carrying war GASES.
especially as the Italian Fascists had murdered thousands and maimed hundreds of thousands using gas in Ethiopia.
The Japanese did the same repeatedly in China a few years later
All using a very few crude aircraft and limited artillery shells.
Yes for Britain, there was the threat of retaliation, but no one knew if that would deter the enemy from a surprise attack
Therefore iOTL 1939, every Briton .. man, woman and child down to babes in their cradle ... were issued with Gas Masks
and
required to carry them at all times.
That perception was reinforced by Art and Literature in the 30's
See the first half of Korda's AH movie "Things to Come". That showed how most expected the next war would be.
Destruction of infrastructure from the air of course, but death sown on the wind being decisive.
Today the film is dated and crude in philosophy and execution (especially the second half showing a utopian recovery).
We may agree today that "Guernica" is better art and longer-lived but in the 30's Picasso was known only to the few.
The flick played at every Odeon and Palais (and the novel from Wells was on every station book store)
And that Chemical Warfare threat was real ...
more real than we in the democracies knew.
Rather than the crude irritant gases of WW1 which had to deployed in huge volumes
the Nazis had early forms of nerve gases that killed in (relatively) tiny doses
and BTW rendered all those protective masks useless .. which the Hitler Clique fully realised.
The only reason that the Nazis did not deploy them was that they
overestimated Allied technology.
In their opinion, the basic forms of organo-phosphate agents were so obvious that everyone must have them
(kept top secret of course, as they had done their own advances)
In late 1941, When the UK threatened to use their CW agents on the German Homeland if the Nazis used gas in Russia
that conclusion was reinforced .. and MAD held.
Ironically, a regime that waged war by terror was deterred by their own terror.