Well M Messiaen was after all born in 1908 was not he?

Do you know I think I missed that bit of the libretto...

That's an intriguing observation, Ruth. Not something I'd thought about before, but then I'm a boy. I will say that my own initiation into Messiaen (which I don't think is entirely unique) was quite 'male', in that it involved loud organ music, the thrilling sound of a 32-foot reed, lots of drooling over how many notes there were on a page and geeking out over modes of limited transposition. I think there's plenty in Messiaen that tickles the parts of the generally male brain that enjoys motorsport.

It sounds like Ruth's on to something.

However, I wouldn't have thought of Messaian as remotely macho, in the way Wagner, for example, might be.

A standard criticism of Catholicism in C19 England was that it was unmanly.  I have a suspicion that the suppression of women in official Catholic teaching might be a feeble attempt to save male face in the light of the overwhelming power of Mama in the Mediterranean home. 

Messaien's Catholicism as far as I can tell, was of an intellectual, French style.  I suppose you could argue that appeal to intellect rather than the senses is stereotypically male.

Messiaen was himself male.

I'm always a bit suspicious of any gender division in the appeal of a certain kind of music. Obviously if the statistics support it, then more men than women appreciate Messiaen's music, but does this actually mean anything? My mum usually uses a study in her stats classes, which shows a strong positive correlation between stork nests on chimneys and babies born to that household, in order to demonstrate that although there may be an incidental link, it isn't necessarily the obvious one for which you are looking. Statistics are whores, basically.

Saint François has no human female cast members for a simple reason (IMO).
Messiaen reduces the drama to a limited number of scenes which operate like stained glass windows.
This means (IMO) that the scenes have to be reduced down as well, removing characters which don't directly progress the plot etc. and prove to be distractions from the central message of the window (I know that not all stained glass follows this pattern, but busy windows depicting the Tower of Babel or the casting out of the money lenders from the temple, are wonderful (and deliberate) demonstrations of what happens when you have many characters in a window). I think that this is what Messiaen does.
How then do you include a female character? I believe that (for example) introducing St Clare to the opera would unbalance it and distract from the central theme of the opera, which leads towards St François's stigmata and eventual transfiguration. Each scene moves him closer to this end.

There are certainly arguments which could be made that suggest that the choice of story for the opera, and the focus that Messiaen chose reflect his male-oriented thinking, but I am certainly not interested in making them. He claimed that he wasn't a theologian, but merely served God. When I read interviews with him, I feel that his acceptance of the doctrines of the church tends towards acceptance rather than critical thinking (you could see that as coming down on the Bernard of Clairvaux side of the argument rather than the Abelard side).