Yes and no, correct they are ambush hunters, and lucky we generally are not on their menu. But the last guy they killed in this county 2 years ago, the cat just walked up to two brothers hiking early twenties and attacked both from the front, killing one and messing up his brother pretty bad.
My buddies were on a trail a few months ago, where I rode 5 days a week for a year, and my buddy heard it crashing through the Manzanita and he took off, never saw the cat, my other buddy who was riding with the first guy, behind him came face to face and had to throw rocks at it, then retreat the opposite way just to get out of there. They both carry pepper spray now mounted on their bars.
I saw a German shepard sized cat last month leap across the trail 40 yards in front of me, was bridle colored. Did not see its tail, so it was either the biggest bobcat ive ever seen, and ive seen 4 in the wild, or a juvenile mnt lion. I stopped where it crossed looking for it, and whistled and it leapt up hiding in tall grass about 20' away and took off through the brush faster than I could get a look at it.
They say its the ones you dont see you have to worry about, and I wear a full face and have a backpack in case of rear attacks. But attacks are very very rare. It took me a few years to ride where I do now alone in the daytime, but I try and not be out alone at dusk or dawn.