Yep, your description of Yosemite is pretty typical. Strangest sight I can remember seeing is a couple taking a baby carriage (complete with baby) quite a ways up 4 mile trail (actually four and a half miles long) late in the day.
Oh, my! The good news is that they were out of their car, and having an adventure in nature. The bad news is that they were woefully unprepared.
Lazy as I am, Four Mile Trail is one of my favorites. Beginners take note. For something like $20, you can take the bus up to Glacier Point, and then hike down! It's the easiest hike that gets you from the lip of the canyon down into Yosemite Valley. You get many gorgeous views along the way, including a closeup trek past Sentinel Rock.
On one such adventure, I watched the sunset along the way, and finished the last mile using my headlamp and flashlight. That's another tip for beginners. You can escape the crowds at Yosemite by starting late, and coming back in the dark.
Here is an easy trick that non-hikers can use. At Glacier Point, you will encounter hordes of visitors. Last time I was there I estimated there were about 400 folks sharing the views with me. I had to wait my turn to get to the front of the stone wall, from which I could photograph Yosemite Falls, North Dome, etc. Most of the people are tourists, folks who rarely get out in the woods. Most, therefore, are quite cautious.
Now, there is a rail that marks the eastern boundary of the viewing area. That's the part that faces Half Dome. Away from the cliff, the rail is just a boundary. There is nothing dangerous about hopping over it. It is also completely legal to do so.
So that's what I did. After a short walk of perhaps 300-400 feet, I was in solitude. By placing a tree behind me, I hid from those above, so that no one would get the idea to join me. Even without this precaution, most of the tourists would have stayed behind the rail anyway. My views were almost as good as those from the official viewing area. I sat for alone for something like 15 or 20 minutes before returning. I had solitude amid a crowd. No hiking necessary.
Every year, one or two people die hiking in Yosemite. It can snow there in any month of the year. Here is a
YouTube video that recounts the story of some experienced hikers who had to be rescued on the Four Mile Trail during an early October snowstorm. It's a typical tale. These guys did it to themselves. (Despite the video's title, no one died this time).
Another place that attracts novices is Grand Canyon.
As a boy, I was one of those novices. My family was there for just the day. My younger brother and I blithely scampered down the trail into the canyon. After about 40 minutes, we figured it was time to go back.
Boy, were we surprised. I know now that we had gone perhaps as far as halfway down (close to 2000 feet vertical), but it did not seem like much on the way down. It took a lot longer than 40 minutes to climb out! At only 10 or 11 years of age, it was frankly too much for us.
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