Sky made a rod for their own backs by making a bunch of promises they couldn't keep when they started out - the commitment to nobody who's been involved in doping ever (proved nigh on impossible when trying to source an experienced DS), and no doctors who have come from cycling (before hiring Leinders) - but the main one was the commitment to transparency.
Many teams do not commit to transparency, and do not get as much stick for not showing it as Team Sky do. Because Team Sky made that commitment, them not being prepared to share their data is seen as reneging on that commitment. And given that, as their performances become ever more dominant, being transparent and sharing data would go a long way to assuage the doubts that the fans have (and Wiggins has shown that he is upset that the fans have), declining to do so only strengthens the implication that there is something to hide.
They must recognise that fans will have doubts about a team that dominates in such a fashion. And they are clearly upset that the fans have those doubts, as we saw from Wiggins' outburst last week. But unless they actually start to revive that commitment to transparency that they talked about before, then what they're doing is saying "hi, we're clean" and just EXPECTING us to hang on their every word unquestioningly, and simply saying "you're making it hard for us to believe you" is an affront - but they refuse to show us why.
Now, I'm sure that they feel that if they posted the biopassport data now, most people's opinion is already formed one way or the other, and a clean passport would contain some information that cynics would overstate and overhype to suggest meant doping, while a dirty-looking passport would be carefully explained away by a variety of theories by some. But if you make the commitment to transparency, you have to expect that one day the fans will come knocking asking you for that information, and what's a better time to question than a time when they're dominating the biggest race of the year?
It's like Lance in 2009. He committed to showing his data. He showed his data after being pressured into it, got wind of some feedback on it he didn't like, and took it back down again. If you're not prepared to hear feedback you don't like, don't publicise your figures. But if you're not prepared to publicise your figures, then don't make a commitment to transparency.