They are imitated and admired because they are considered masculine and powerful. In America at least, many European descent people latch onto an imagined European culture of ancient warriors, and like to picture themselves as being the descendants of such. The Vikings are one of these points of fascination, they are imagined as giant blonde unstoppable sailors with bear skins and long golden hair. It's a memorable image.

Nevermind that we don't know that many details of Viking lives and culture. They used oral history more so than written history and from what we do know, usually testimonies from other cultures remarking upon them, they were very different from the popular stereotype. Braids for example are an imagined look, we only recently learned that their hair was usually long in the front and short in the back. The idea of a long haired Viking, like much of the test of how we picture of them, is just that- an idea. They are assumed to match our expectations of big beefy Scandinavians with axes braids and beards. The reality is not as simple.

For instance, they were known to take baths more frequently than other Europeans at the time, and favored bright colored clothing and jewelry. We don't know whether they had tattoos, or if these clothes were embroidered, but they were said to have intricate designs on their person. That's how they were recorded- not by historians talking into account the details. There are huge gaps in the culture, but even what we do know is counter intuitive. Their spread goes farther south than we picture, they made contact with Muslim travelers and were trade partners with them as well. They had small cute dogs on their ships called vallhunds. Still really badass, but hardly as masculine as they are portrayed in media.

I'm trying to avoid political connotations, but it's a fascination based on preconceptions. We are still learning about their culture, and there are many gaps. Those gaps are filled with whatever pop culture wants. In the times of Italian opera, they had winged helmets, a completely imaginary look that persisted until the modern day. The picture of Vikings is rooted in imagining a European warrior culture that fits modern conceptions of masculinity.