Whats with highlanders and romance novels?

I don't get why so many romance novels feature highlanders? Every other romance I see is called "the (insert adjective here)highlander" . Please explain :)Whats with highlanders and romance novels?
Certain groups tend to be perceived as romantic-- Native Americans, Vikings, titled persons (duke, earls, princes). Why? Many theories. One is that they are seen as heroic warriors who are distant and uninterested in love so the book's heroine gradually wins their love and these big brave fighters turn into gentle lovers. With Highlanders and Native Americans, you also have the air of loss or upcoming loss: the Native Americans' loss of tribal lands and the attempts to eradicate their culture, the end of the buffalo hunts, etc. and with the Highlanders you have the terrible loss at Culloden and the English takeover. The Highlanders were reputed to be wild, fierce warriors, very clan-oriented, proud; the lowlander Scots simply didn't cut such a dashing figure.Whats with highlanders and romance novels?
Kilts make it easy to write sex scenes.Whats with highlanders and romance novels?
They don't even wear anything under those kilts, you know.
Because it sells. Truth is that any romance book lover that gets hooked on Highlander stories has a hard time letting go of the "fixation". Fact is that this type of historical romance has been popular for decades, but it does seem like it is reaching a peak. I read quite a bit of historicals with Highland settings. And they are not limited to just historicals, many are paranormals (time travel). Those are my preferred ones. If you evern want to give it a try, look for Karen Marie Moning (her older books, not her new series) or Lynn Kurland.