OddOne:
I seem to recall the reason this structure wasn't replaced with frangible is that it was sited on a flood plain - about 15' below runway level. It would have been washed away regularly if it had been made frangible.
At least that's what I heard. Think the report discussed it in those terms too.
Reducing the declared distances... well that's another can of worms, commercial worms as you say...
R1