it's true in experience. I'm a single guy. I date around. Most women I meet think gardening makes me queer. It is not considered a desirable hobby for a man. And many men who don't garden, also think it's queer/feminine.
People who do garden, don't see it that way, of course. But every garden group I've ever met up with was 70% women, and most of the men were not 'manly'. I myself am not a manly guy.