I am a local and go on several solo day trips. I have only gone on one overnight solo trip. I have to admit I did get lonely especially in the evening, so I sat at the hotel bar and talked to the bartender and watched football and Sportscenter.
However when I am in the parks, I take the opportunity to do things I would never do if I had the kids or dbf with me. I stop and "smell the roses". I check out art exhibits in EPCOT WS that I haven't seen. I am able to ride the single rider line on RNRC at DHS several times in a row. I do not have to worry about getting to DHS at rope drop for TSM because I don't ride it solo.... I am able to eat at the restaurants I want to try without having to worry about everyone else's opinions/likes/dislikes.
I certainly think it takes a certain type of person to go solo. Some people really enjoy solo trips, some do not. I enjoy dining by myself at restaurants. I go to the movies by myself regularly.
Dbf will go with me for special occasions. He loves Food & Wine and Flower & Garden at EPCOT. We are going for our anniversary next month. We go for our birthdays. I went solo for Christmas because I love the decorations and wanted to see them. He could have cared less. We have an understanding and it works for us.
The kids of course would love to come with me for every trip. However I go solo usually when they are in school. We have trips for just the three of us and is all about them. Whatever they want to ride, whatever park they want to go to. Again, we have an understanding. It works for us.
I think this may be different for us, though, if we lived farther away. Luckily we only live 70 miles away from WDW.
On my overnight solo trip, I met up with 2 different DISers who were also solo. Each family actually gave them the Disney trip to them as a birthday and/or Christmas present. One is from Canada and the other is from Indiana.