Since there are only 5 Axis shooters, the reason I don’t scramble is that your chances of getting diced in this particular battle are high. With the full commit you’re facing 7 shooters and 9 hits (DD CA 3 FIG 1 TB 1 SB, (CV)
Italy loses its only strikeforce at this point (whether you “win” or “lose” the Axis planes are usually lost). That may still sort of happen because most times there are either 2 Allied ships there or 2 figs and the carrier, so you still lose the CA DD SUB on the attack but at least you don’t lose those two fighters. Without them, Italy is helpless in the longer term because its going to rebuild with the only money it gets before it gets overwhelmed.
Germany could sink more airpower into mopping up or supporting this area, but that’s usually a loser too because Germany doesn’t have any subs to soak hits until later in the game. So then its a pure air attack against whatever is left in the med, you’re trading planes for junk usually…
The best scramble IMO is over Scotland, because the pat opener is to do 6 hits to 111 and 8 hits to 110. With just the 6 attackers, if Germany flubs its first run of dice, the allies can stop this attack cold if they get 2+ hits on their first round.
Additionally, if UK brings anything less than the full ## of units that can come, you should scramble. But if they bring the full ##, the odds and momentum falls to the UK quickly, with only 1 transport and $10, Italy is pretty much at a loss to respond to what you do once their initial planes and ships are dead.