Jcjeant,
In supporting your argument that authorities may have dragged their feet on finding the wreckage, I point out that one major difference in finding AF447 and the Titanic, lost nuclear subs, needle in a haystack, etc, is that AF447 had a 37.5 khz beacon pinging for 30 days, and the others didn't. The searchers through oversite, incompetence, lack of proper direction, equipment, or personnel, didn't listen for it properly. Chu Chu pointed out that it was reported that the Nuclear sub that listened for the ping, wasn't optimized to 37.5 khz. As a cynical american, I interpret this to mean that they had submariners listening for the ping with headphones, without the 37.5 khz being downconverted to a frequency they could hear. As we know, humans can hear up to 18 khz if they are lucky, and certainly not 37.5 khz . To spell that out, would have drawn ridicule to the investigation, so the euphamism "not optimized to 37.5 khz" was reported. The United States loaned the investigators some proper equipment to listen for the ping that was towed by a tug, but the french were in charge of it, so I don't know what it's search area was or if it was used properly, if used at all.
Anyway, bottom line, there was a beacon to home in on, and they didn't take advantage of it. Sure, some might say, "Maybe the pinger didn't work?". Doubtful. Besides, the first thing the BEA would have done, if the pinger showed failure, when the black boxes were discovered, would have been to shout that fact to the mountain tops, so they'd have a good excuse for what took so long.