I like to jump in my hammock without worries that the suspension will snap at any moment. Using cordage that doesn't even meet the most mild safety guidelines is just something I will ever do. I know for a fact that paracord will damage even hardwoods. I have a small forest on my property that I frequently hang from with friends and I have noticed several marks left by the suspension of my tarp lines which are very similar to paracord in diameter. If a tarp line will mark up a tree real bad then I am pretty sure a hammock suspension will too. Webbing really helps lessen the damage...
There is always going to be a difference of opinion on this subject and some people will stick with what they know and that is just how it is sometimes.
I'll post some picks of the tree damage on my property, later this week.