I have done two solo trips and am about to do it again in less than a month! Those trips even played a part in inspiring me to join the boards. Even if you only do it once, it's something you should try and experience. There's nothing quite like being able to do your Disney vaca with only having to keep yourself happy.
The added costs of going solo can be a bit scary at first, but when you get to do whatever you want whenever you want, you'll realize it is well worth the investment. Treat yourself!