At least know what effect it has on trees when you pave over the roots...
I think trees in urban areas, what with sidewalks and lots more paving... those trees are generally considered to have a shorter lifespan.
I live in an old neighborhood that is losing mature oak trees with paved over roots, and the city is replacing them with younger oak trees. I think the thinking is that if we get only 60 or 75 years enjoyment out of the newly planted trees instead of 120 years, that will be ok.
The discussion about whether the barners mistreated these trees seems beside the point to me...they can treat their trees any way they please as far as I'm concerned. If the trees were being mistreated, that isn't an invitation to poison them, or to "rescue" them.