Very well sir, I'll try to enlighten you as far as my limited abilities and knowledge allow.
11° ANU is taken from A320 Ditching checklist and per Merriam-Webster "to ditch" means "to make a forced landing (of an airplane) on water". All the ditching checklist I've came across dealt with forced alighting on water therefore "water ditching" looks to me as a good example of redundancy in writing. Now when I've touched the subject of checklists, different aircraft operators have different ideas how the aeroplane should be flown in normal circumstances and that's what the SOPs are about - normal procedures. When it comes to emergency and abnormal (alternatively called: "following failures, non-normal etc.") procedures, everyone is interested in following the procedure that gives the best chance of survival and this usually boils down to one and only procedure promulgated by the aeroplane's manufacturer. I don't know whether Airbus Industries' just calculated the optimum ditching attitude and technique or actually experimented with A320 scale models but it seems that capt Sullenberger's successful ditching has validated the procedure, whatever it was.
To make it even more clear: there's no SOP regarding the ditching. There's no tribal knowledge regarding the ditching. Ditching is dealt within emergency sections of the flight manuals and not a single one I've come across makes emphasis on alighting with low AoA. It seems that "perception that a tail strike into the water is the safest scenario" is actually the correct one.
Incidentally, 10° AoA is not much for aerobatic aeroplane but is sure a lot for transport one.
If I may be so free, I'd like to ask you: which part of my post did you find caustic, sir?