Casinos in real life? They are relics from an old time when gaming was different. And this idea that women are mostly involved in fun in these kinds of places? It's ridiculous and almost insulting!
Online tools are the future because humans have always been more interested in the virtual than the real. So, your coworkers play slot machines? Good for them. It is both narrow-minded and stupid to say that women like these because they don't know how to do maths. People, both men and women, are complicated beings who are influenced by many things besides "luck" or "strategy." Look deeper into the complicated web of what drives people before you make assumptions about them.
With you 100%, women are just as likely to play at casinos and they are likely to do it for the very same reasons. Any point made on why half of the population does anything is ridiculous and probably unfounded.
I asked for the research mentioned in the OP but I got nothing in response. All hearsay.
Since this is a discussion thread I think most comments will be based on personal observation and little research so the ops may not be able to provide you with any links that can support his claims, but even at that, we all know the low percentage of women involvement in gambling and this challenge have been ascribed to public stigmatization and if the individual doesn't check everything out may result in more or less avoided by others in the society.
All though this is not the same with every state or country because we have some countries where gambling is legalized and women's participation in active gambling is quite noticeable without any form of discrimination like in other parts of the world.