Why is romance seen as "girly"?

Men can't have non-violent feelings

I think girls in general are more interested in things involving interactions, relationships between people. Whereas boys lean more towards nerdy stuff, things that are more remote from the everyday mundane life. Girls have a more grounded approach to life whereas boys like to indulge in abstract things and fantasy worlds.

So it's not that boys are not interested in romance, but I think they're only interested in their own romances, not in other people's or fictional character's romances. I think that's why they don't like romance as a genre in general. It's too mundane.

I guess because more girls are into romance stuff then boys so to delve deeper into their target audience romance stuff contains more stuff that is oriented towards girls. The stereotype reinforces the stereotype in a circle.

It's the same way for games a few years ago were heavily preferred by boys so games were created to appeal more to boys (lots of shooters, the generic bald space marine main character, tons of violence etc). Though games these days have a lot of female fans and games have progressed so aren't all super macho shoot everyone type games.

I think it depends on how a story is written. Most action stories also feature a romance aspect, it just isn't the main focus.

Pure romance novels however are usually written specifically for women, and since there usually isn't much in the way of a plot, conflict is instead created by making characters act and react in ways that are completely illogical and infuriating.

A Woman might put up with it because she likes the part of the story that is the promise of a happily ever after with the guy of her dreams, but for a man who is not interested in the guy, there's nothing there. No plot, no characters to identify with, nothing.