Bud, I am so with you on this. I'm going to be there my first time in Sept. I do a lot of travelling on my own as well (I had moved to a new country for work). I have met several good friends who all have their own crews, but I still frequently go out, and vacation, by myself. It's because I like the mobility, and the chance to meet cool new people to hang with, while still having the opportunity to just chill out alone, when I get tired.
Sometimes I do run into people who can't grasp this, or who'd rather be left alone (I do understand their point-of-view... there've been many times in the past when I was with my mates from back home, and we'd think of lone travellers who were trying to chat us up, hmmmm, quite strangely......my karma, eh?) But more often than not I meet people who easily make great friends!
I was in Bali two weekends ago and it was the same story - a mixed bag. There were people who were cool to chat and hang with, others who seemed to want to stay by themselves, which was cool too. But I'm hoping Ibiza's going to be even better, with more like-minded people, and reading all the posts here, it sounds that way indeed ..... so let's go and have ourselves a party! 8)