I think you're simply getting wrong impressions from old people and the attitude toward them.
Go show some more kindness to you grandparents, offer your grandma to make a cake together and listen to her life stories.
In my University campus there are plenty of old people working as assistants, security guards. They are smiling, they are having fun. And I can't see why not, I might have enjoyed a lot of the things there if I didn't have different goals.
I got fun chats with people there who simply saw me hanging around with a cat there which they all love and treat daily.
Sexuality has nothing to do with happiness. Well it can help it, but it's not the main thing for it.
I think you need to reread the thread if you think I mistreat old people. The question raised here is whether or not older people still have active Libidos. And if so how miserable must many of them be to not be able to do anything about it? Like someone else said many older people have the same minds they did when they were 20, but how do we treat them? Like they have the minds of 80 year olds! bit of a contradiction isn't it! Let's stop being hypocrites and discuss how we change this.