I am going to provide an alternative perspective.

Traditionally, yoga is to be practiced in seclusion after obtaining one-to-one instruction from a competent guru. There's a saying in India: keep your sexual activities and your spiritual practices a secret from others.

This group practice is a modern innovation of the three Mysore gurus (TK, KPJ and BKS) originally inspired by army drills and gymnastics (only in this respect of group activity, I specifically state) designed for young, fit people.

I say this because some ill-informed fellow said in a collapsed comment here that the British army invented yoga in 1900 CE! What the actual $%&#?

Coming back to the issue of men in yoga, I am going to share an observation here:

Most (note this word) women are enthusiastic when it comes to the poses, but I have not seen many women do pranayama or dhyana with the same enthusiasm. At the same time, I have seen more men doing dhyana and pranayama than women.

This is because deep down most women are interested only in the relatively gentle workout these asanas provide - nothing more. They just want to tone their muscles and keep them toned, they don't want to build muscles. (Nothing wrong with that, though)

That is the popular western view of yoga. A gentle workout. Nothing more.

Consequently, the men who frequent these yoga studios in preference to the gym are either more in tune with their feminine side (you can see the PCness dripping in this sentence, can't you!) or are serious practitioners who progress to the higher limbs in due course.

But, in the higher limbs, you get to see more men than women, anywhere in the world.