It seems likely that there's a selection process at work here — if asthmatic cyclists are the only ones who can legitimately use steroids, then we can expect to find a lot of asthmatic cyclists at the elite end of the sport. This could well have been an unconscious process rather than a deliberate strategy, but who knows? There are a lot of people in the sport who are cynical enough to have spotted the opportunity.
(As an asthmatic cyclist myself, I sympathize, but since I don't race I can just keep the intensity low enough to avoid having to cough up buckets of mucus out of my lungs after every ride.)
Diagnosed asthma is very significantly over represented in the most successful populations of elite sportspeople - I use that phrase rather than asthmatics, although clearly some are the latter also. That is not consistent with the impact of asthma on respiratory capability and it's an important question to ask whether the drugs are leveling the playing field above the norm for both those with childhood induced asthma and those with later onset exercise induced/identified asthma.
One question I think is worth pondering is whether it is reasonable to allow someone to use drug treatment to increase their athletic potential beyond the natural genetic limitations they face - this may be asthma, or just wanting more respiratory capacity and less fatigue/faster recovery, but it might also apply to the lady with naturally low haematocrit and her EPO TUE or the low testosterone 'sufferer' and his testosterone TUE etc etc. What about the intersex athletes competing in the female classes?
The public media image is that sport is about natural talent and hard work. Using drugs to 'level the playing field' does not enter into that equation. Sorry, but I'm no world champion either. Genetics matter.
Personally, I've become jaundiced in my view of Team Sky, British Cycling and British Sport in general. The fawning nationalism of the Olympics did nothing to dispel my doubts and cynicism. Wiggin's TUE does nothing to make me feel more comfortable, but looks very confirmatory. Asking the Times to criticise Team Sky seems a long stretch, given its ownership, and I wonder whether they are hanging Wiggins out to dry, while trying to protect Sky, British Cycling and the rest. Maybe, they'll upset Wiggins enough for him to tell a whole lot more.
I'm sure LW&B can add something of greater value and real knowledge to this.
Mike
Edited to add - read up on Alberto Salazar and the Nike Oregon Project for some background in a non-cycling field.