You technically don't ever seen other hikers unless they're going the other way, and they're usually pretty cool and considerate. You can see the expressions on their face and body language and their gear and can get a basic story about them from that, making it cool to see them. I rarely catch up to other hikers nor have other hikers catching up to me, going in the same direction, unless in a group with young kids in it. On occasion, some pass along some gossip that there's some *******s or a large group on the trail that I should look out for and it's sad when they're identified as mtn bikers.
When I see equestrians, I'm usually polite, and marvel at how healthy, strong, and good looking their horses look, but then when I see the gouges in the trail and the horse poo... I definitely yield, since I don't know how to really act around horses and know they're a bit faster than me. Amazing to see them go down hills.
I know hikers have the right of way on a trail, but I rather step off the trail to let any faster folks pass, no matter what they're riding or not riding, and in some areas, that's kind of inconvenient. I guess since I'm trying to be considerate. Bikers are typically the fastest, and I consider it an interruption every time a biker goes by. The most annoying type of biker is the one that quietly "sneaks up" from behind. I put a bell on my hardtail, since I didn't want to be that kind of rider.
If I were a local to the PCT and hiked it, I simply would just switch to biking, since hiking would no longer be appealing due to the trail being used by a "bigger beast". If there are less hikers, would the wilderness areas of the trail get neglected? The portion close to me goes through Big Bear, which has all sorts of good riding nearby, but I can think of epic rides going north along the PCT.
People say they feel unsafe riding their bikes on the road, while many others insist that it's safe. On the road, you can ride to the right and drivers can give ya room without much inconvenience, but roadies still prefer lightly traveled roads that feel safe, due to having space to ride without dealing with traffic going in the same direction. It's sort of the same feeling with hikers, except that it's hard to go nonstop with bikers passing by in the same direction and not all bikers actually yield to hikers going in the opposing direction. I know there are times where my companion has screamed out in fear as bikers skid to a stop (but laugh afterwards, embarrassed by their reaction). Just easier to give plenty of room to let people pass, since people look out of control when they slow down.
What would you do as a biker if you saw a big animal on the trail, that wasn't hostile to humans? Hikers feel like the rabbits, deer, birds, etc. on the trail, and feel like it's best to prepare to flee. If hikers had the strength, size, and mass of a moose, it'd be a different story.
I've been known to be rude to cyclists that don't yield. I might say something like "thanks a lot" in a sarcastic manner when they slow down, see that I am hanging on the edge of side of the trail with exposure, and then skid through. It's even more worrisome when it's a newb and he's shaking all the way down, maybe dabbing and waddling. Then there's the Strava guys... That's why I made an earlier comment that I found it interesting that IMBA was encouraging the creation of sustainable bike park and flow type trails (for bikers only) to help keep aggressive riders from abusing multiuse trails.
Hikers do feel unwelcome on multi-use trails. Rather just stick to hiking up mountain peaks, where it's typically far too steep and rugged to ride unless you're a masochist or something. Figured I'd try trail running and bouldering again once it cools down or something.