There are good horsemen and bad horsmen. There are places suitable for horses and others not. I have used horsepackers for re-suppy and also to haul me in from where I walked out. Also used horse packers to help out when my kids were at that awkward age - too big to carry and too little to walk much distance. Each wilderness area must be considered individually. I do not think you can make a blanket statement.

As for bikes - it is not wheels or no wheels - for me it is speed. Even good bikers speeding down a hill on a blind corner can easily hit a hiker. Bikes are OK where the trails are wide enough and visibility is good.

I have carried an elk out on a pack frame. Was 3 months pregnant too - walked a bit, puked a bit, eventually ex-hub and I got two elk out 8 miles. My pack weighed about 100 pounds, his close to 150. My pack frame got cracked. Getting the elk out was not an option - it was our entire winter meat supply. We lived on less than $3,000 a year. A cart would not work because it was a very rough trail and some off-trail. I can sympathize - if there is a nice wide trail, I see no problem with a cart. You will be going way to slow to run anyone over!