I've traveled alone a number of times for some of the same reasons the OP mentions. Several times, friends have suggested we travel together and I say, "Great...I'm planning a trip in [time of year] to [place on Earth]...let's go." And they get all excited, and I plan the trip knowing in the end, they won't have the time or money.
The only organized tours I've done are cycling tours. I made a good friend on one of them, and now we've traveled together on other cycling tours (straight guy, though).
I've mentioned the reasons why I don't mind traveling alone versus with someone or on a tour a couple times in these forums, but to dust them off again...
Erik said in another post
1. You get to choose where to stay. Price, location, quality. It's up to you.
2. You get to choose whom you are going with and with whom to share a room.
3. You can be flexible. Want to sleep in one morning? No problem. Want to stay out late? Go ahead. Want to eat somewhere that serves the kind of food you like? Do it. Couldn't care less about seeing the tallest Gothic steeple in Europe or the largest stained glass window in northern England? Do something else instead.
4. Hate the people you're traveling with? Go separate directions and meet up later.
5. Want to really get to know an amazing city? Stay there longer than a day and a half. On organized tours, you're going to be shuttled around on buses to tourist sites and stay there long enough to take pictures until you're shuffled back on the bus to the next place you're only going to spend 30 minutes at.
6. Want to meet and talk to locals? Good luck on a tour bus or in the middle of 30 other loud, obnoxious Americans.
I could probably come up with other reasons, but that's why I always do my own thing. Before the interwebs, I used a travel agent to help out with hotels, but now with online travel sites and crowdsourced reviews, there's no mystery to what you're going to get or what is available for you.
I've traveled on my own quite a bit and never worry about getting butchered and raped (much). I leave the signs of being a tourist like maps and guidebooks in the hotel and i try to always look like I know where I'm going even when I'm horribly lost. If you look like you're lost, you'll be a target. I also just keep aware of my surroundings and try not to get out of control where someone could take advantage of me. Basically, a little confidence goes a long way.[/quote]