I don't think that stereotype is helpful. For starters, we already knew that 75% of cycle hire users are male. We also know that cyclists tend to be from the more affluent social groups, and we know that the majority of people in central London are white. So the profile of the average cycle hire user is probably little different from that of the average cyclist in London.
There's nothing exclusive about Cycle Hire. Anyone can hire a bike, providing they're in posession of a credit or debit card. It would be great to get more people using the bikes, but to do that we'd need to tackle the barriers to cycling of all sorts in London - this is not a class issue, a race issue (Irish names aside) or a gender issue. It is an asphalt issue, a segregation issue, a road danger issue.