OK, you want to go there?
I worked at Bass Central for 5 years, sending and receiving basses at the clip of a conservative average of 3 per day, 5 days per week. So, the math here would be 3 (basses per day rec'd or shipped) x 5 (days per week) x 260 (weeks per year, times 5) which comes out to 3900 basses. Every single one, both incoming and outgoing, tuned to standard pitch.
I have now worked at Roscoe Guitars for 11.5 years. We ship an average of 1 instrument per day. So, 5 instruments per week multiplied by 598 weeks is 2990 basses.
That adds up to (approximately) 6890 bass guitars that I have either shipped or received since about 2000. I'll give myself the benefit of the doubt and estimate that in reality it's really well in excess of 7K; but even if I have grossly overestimated the number, and you knock of 20% of that number, it is 5512 instruments, or more than 10 times your upper estimate of 400 shipped. I would posit my sample size is truly significant. Yours, while not utterly insignificant, is not really enough of a sample size.
Never have I, or anyone at Bass Central, here at Roscoe Guitars, at any manufacturer I am aware of (I am actually on exceptionally friendly terms with pretty much everyone in the industry - we are not nearly as competitive as you might think.

) have ever had a single example of shipping damage due to shipment with the strings tuned to standard pitch. Due to mishandling and less than sufficient packaging certainly, but not tuning to pitch.
I'm really not picking on you, I'm merely trying to point out that your position is not supported by any actual statistical evidence - only anecdotal evidence, with no control. I can cite controls, we receive repairs here with the strings detuned, and when I worked at Bass Central, we received returns and trades with the strings detuned, and I have indeed seen issues, not many truly bad ones (without an actual full log, it's impossible to be accurate to a decimal point, but a quick back of the envelope scribbled calculation would put it at between 1 in 12 and 1 and 15 - not awful, but worrisome) , but far more than the zero issues that I have seen from an instrument being shipped with the strings at standard tuning tension. ALL of them required far more attention to return to proper playing condition than was reasonable, based on the fact that leaving them at standard pitch typically meant the instrument played very close to "perfect" when removed from packaging.
Short version of the entire discussion is this: DON'T DETUNE YOUR STRINGS WHEN YOU SHIP.