I think the answer, although the under lying reasons are complicated, is because Downhill, on the north shore, is almost dead. Large wooden structures are not allowed. It has been relegated to illegal trails on Seymour. You can choose to ride these but face the risk of being ticketed by Park Rangers for ilelgal activity - the only legit DH line on Seymour are the CBC, Pingu/Boogie lines which are slowly being gentrified - everything else is now accessed by pedaling up - and most of those who pedal dont want to ride the C-buster/Severed type lines on the little bikes used for pedalling. The paranoid politics associated with wood structures has basically killed wood. Even simple ladder bridges get the hair up on Landowners backs. Fromme has no full DH lines for big bikes - and Cypress, although currently the only place to ride big DH lines on the shore, is under attack from the powers that be and is slowly being gentrified as well.
You want wood to huck off? Head to squamish or the valley. But dont look for it around here.
I know it's beating a dead horse and going to fall on deaf ears, but two things that you are massively oversimplifying/ignoring:
1: Liability. Like it or not, we are users of the land, not owners, and if someone gets hurt, then there is a risk of legal action to cover losses, and no-one wants it to come to that.
2: Maintenance. The trails prior to a couple of years ago were in really rough shape, they are getting repaired, re-built to last with volunteer labour, which is limited. Fixing a drainage issue will always be more important than building a new stunt. To quote Mark Wood, since he put it best, 'You need to make the cake before you can ice it'.
Another point that you didn't consider is the audience, there aren't many people left who [HTML_REMOVED]i[HTML_REMOVED]want[HTML_REMOVED]/i[HTML_REMOVED] to ride big features any more. I've hiked up the Dentist on Eagle a fair bit lately, and it's in relatively good condition, everything is technically rideable, but the wood is super green just because no-one is riding it. I used to love that trail, now, I'd rather pedal and go on a big adventure, and I believe that I'm in the majority with that sentiment.
No one hates wood structures, riding has changed (for good or bad) and there just isn't a massive need or want of them any more.