Isn't that a limitation?

I haven't written my main post for the day yet; I'm still arguing with myself as to what it will be about. I do have a story from a meeting I just left that I thought was worth a "mini-extra-post."

I just left our bi-monthly (if that means twice a month, and not every two months) Research Conference. These meetings are more than just presentations; they are meant to be presentations with discussions -- the merits of a proposed study, the implications of findings -- one person presents, and then the group contributes thoughts and ideas. Anyway, a doctor not from our "group" was presenting a proposed clinical study to our doctors (we'll call them attendings) and specialists-in-training (fellows). After the presentation, we probably spent 45 minutes in discussion of the merits and shortcomings of the proposed research. This is a clinical study -- not my area -- so I didn't contribute much until the end of the talk. Near the end of the discussion, the following conversation occured:

Me: Your study only involves men. Do you see that as a limitation of your study?
Presenter: No. (He then proceeds to tell me that the relationship between diabetes and cardiac events in older women is confusing, and that women are protected from cardiac events in their younger years, so really, he didn't need to include them.)
The fellows and attendings go on to tell him that he is wrong in his assumptions.
Me: Can you apply your findings from only male patients to female patients?
Presenter: No.
Me: Then it is a limitation, isn't it?
Presenter: Yes.

How is it that a person can think that the gender bias of choosing only male patients for a study does not present a limitation to how the results can be used when he knows that he can only apply any conclusions he draws to only half of the population?

I was glad that our attending doctors and fellows tried to correct his misconceptions. One even stopped the conversation later, and returned to the topic, telling him that modern studies include both men and women, and that his study would be strengthened by the inclusion of women.

Although he (the presenter) kind of lost me all together when he called all people over the age of 45 "elderly."