I do a lot of solo, off-trail, long trips (like 14days). I prefer to have company mainly for safety reasons, but if I were to always depend on a group I would do a lot less. Solo backpacking does carry more risk, albeit smaller than you may think. You need to accept this risk and be responsible - make it easier to find your body. All comments regarding leaving your trip plan, have bright stuff so you are easily found, become proficient at navigation before going off-trail, etc, are good points. Solo in backpack in environments that you are familiar with. This is no time to try off-trail if you have never done it. Start small and work up to longer and harder trips.

I really hike safer when solo, because I know there is no back-up. I tend to get hurt less, BUT, IF I get hurt, things are more serious.

A lot of us solo, but to say it is as safe, is denial. Statistics are in your favor, yet, statistics really mean little when YOU are the 0.01%!!

Aside from the safety issue, I am seldom "lonely" when I solo. I have been 8 days without seeing a single person and it really does not bother me at all. I think you have to evaluate your own personality and be realistic. Probably one reason I do not easily find backpack partners, is that I am a bit of a loner, and am more intimidated by asking someone to go with me than just going myself. Very out-going people do not seem to have any problem joining a group or going on the internet and finding a backpack partner.

By the way, I do not consider something like doing the PCT or JMT "solo" as really going solo. When you are on one of those "big name" trails you are really hiking by yourself in one big unorganized group. There are a lot of highly used trails that going alone is not a lot different than being in a group per se.