I personally have resisted the dx because it will cost me money. Also, I don't believe that it would change anything. If perhaps I was not diagnosed with AS, I still cannot see myself ever having normal friendships with a lot of people, or suddenly becoming social, or any great change in my personality, because those things just do not appeal to me. Friendships and social situations are torturous and full of obligations which bring me no joy when I fulfill my side of being a 'friend' or 'conversationalist'. I prefer having only one or two friends (people who I grew up with), even if they do live back in my hometown and I only ever see them once or twice a year.
If I was diagnosed, it would not change anything either as I am doing all that I can to improve what little life I have at the moment, so having a dx would not make me 'try harder', or bring me relief because I have already accepted who I am, not that it doesn't depress me terribly, but I have accepted myself more or less. But, thats just me....