There's a strange obsession that humans have with hair. Most people spend amazing amounts of time taking care of their hair and, in many cases, outright obsessing about how it looks. Hair care is a billion-dollar industry. Barbers, hair salons, and hair products are all over the place, everywhere.
There's also many cultural stigmas related to hair in many cultures, to some extent even in our modern western one. The most archetypal one is that many women feel shame if their hair is cut short, or they lose it. There are also many traditional views on hair still persisting in our modern culture (although diminishing), such as that women should have long hair and men short hair.
I myself am a highly pragmatic person. Function always comes first, aesthetics second. When I'm buying clothes or shoes, the most important aspect in my purchase decisions are comfort and functionality, aesthetics being only very secondary.
The same goes for my hair: What is the most functional hair style? Shaving it all off. It's extremely easy to clean, it's extremely easy to dry (both because there's almost nothing to clean or dry), it doesn't require any care, and it doesn't get in the way of anything. A super-short shave is by far the most pragmatic and utilitarian haircut. I couldn't care less what it looks like.
It's also very useful economically, because I can easily cut it at home for free. I haven't spent a single cent in haircuts for almost 15 years. (The last time I spent any money on anything related to cutting my hair was the hair trimmer I bought back then. It's still working fine.)
But not so with the vast majority of people. They really obsess about their hair, and most of them wouldn't cut it off even if they were paid to do so.
Personally I also find shorter hair more aesthetic than long hair, both on men and women.