It took them 2 years to find the Air France plane that went down near Brazil.
The ocean is a big place and a plane isn't very large

The thing with the passports freaks me out. You would think that with the ease of running checks on passport number through interpol that ll passports would be run through.
TBH I think it's probably just a co-incidence that the fake passport guys happened to be on a plane that crashed. I hope they can identify them so their families don't spend forever wondering where they are