Used to be staunchly anti-sidewalk for bicyclists until I got my bike. The path home for me (the one with the most bike lanes) is a little iffy for approximately the last 3-4 blocks. My street is striped for sharrows, but the bike lanes are about 3-4 blocks away. Block #1 is a low traffic street most hours of the day (it is busy during the AM commute with people heading to the freeway, but empty for most of the day otherwise. This block isn't a big deal. The next block is where it gets tricky. Leading up to that street is a very weird 5-way intersection on a major thoroughfare (6 lanes, with cars frequently going 40+). Right after I got my bike, I attempted to bike the one block to the bike lane, which requires a right turn. The intersection is also a bus stop. Well it was really scary, and I made a pact not to do that again (unless it is a quiet Sunday). When I am headed home, the other side of the street is worst, on the up note there is a left turn arrow (which hypothetically I wold use). The problem is the turn arrow is pretty short, only allowing 3-4 cars and the light cycle is really long. So the cars are not going to be patient enough to wait for people on bikes.
When "leaving home" I take the parallel street for a block, and that leaves me with 100-200 feet of sidewalk until the bus stop. When "returning home" I don't always have the energy to use the same route (it is a steep hill in the other direction, it is more like a dip, and when you finish the street you have a semi-blind corner. Cars are infrequent, but they tend to speed to catch the light.). So I decided to take the sidewalk for that block. The corner with the bus stop can be a little busy, there is a bar on the corner with lots of loitering from 5pm on. But otherwise the sidewalk isn't heavily used at all, particularly at night when I tend to go home. I compromise by pedaling pretty slowly, just a bit faster than walking pace, so I don't blow by any pedestrians and catch them off guard. This feels a lot safer than navigating the busy bike-lane free street.
I actually sidewalk bicycle SOMETIMES. I would be a liar if I said some roads still give me gears. I haven't mastered riding next to a car thats about a foot away yet.
You can claim riding on the road is safer UNTIL you are almost hit a by a car.
I ride on the sidewalk when there's a ton of cars on the road. Seriously, where I live, go out on the road on a bike during rush hour and you're suicidal. Semi trucks and cars fly by. I've tried it once. Won't do it again. Cars will honk their horns at you, and sometimes yell at you. A semi passed me once with about a foot or less room. I was like oh crap this is a bad idea and got right back on the sidewalk.
Usually there aren't too many people walking on the sidewalk so you don't have to worry about that where i live.
Now when traffic is less "why I ride at night most of the time" I use the main road simply because it's smoother, and cars can actually move over when they see you.