I don't have any problem with Sintas/Ailyn itself, just the way it happened--it's okay for Fett to have had a wife and kid, but I don't like how it was so disfunctional. I recognize that it's perfectly believable, considering his character, but if I were the writer I would have given him a happy marriage and a connection to his kid. Sure, it's sappy for him to have a happily-ever-after. But his life was awful already (Jango dying, him having no friends unless you count Dengar) and I think it would have been nice to give him just one ray of sunshine at some point during his pitiful existence. I would have liked to have seen more compassion from Traviss and the other writers.
We like to think Fett's only interest in life is his work, but humans are social animals, and I refuse to believe that he can be happy without some sort of casual friendship etc. And I do want him to be happy. I don't want him to be overloaded with angst in everything I read. I liked Bloodlines (excepting that some things Fett said and thought were really out of character) and was very pleased with the ending of the book. For that reason I can accept the canoninity of Ailyn/Sintas. But that doesn't mean I have to like Ailyn personally.
Estuans interius ira vehementi SEPHIROTH!