Iv'e noticed that many if not most Polish guys here in the UK have very short hair.
I like having my hair short by I have never shaved my head -
short hair especially for me is simply practical - when my hair grows longer it gets curly - for me it's a serious nuisance - I can't be bothered with combing it - after washing short hair you don't need to dry it with an electric dryer - drying with a towel is enough
as for shaving your head - well - I simply don't get the idea - seems pretty odd to me - that is also a question of how long you need to leave your hair so that you do not look nearly shaved-off (I don't personally like that kind of look too on myself) - from what I have learned people with shaved heads look more aggressive - I doubt it is a conscious choice most who do do it subconsciously - to look more dangerous/aggressive
there is another side to the practicality of cutting your hair short - many do it with the help of their friends saving on a visit to a barber (electric haircutting machines get there use here and these can be pretty cheap) - in England a visit to a barber sets you back at least 10 quid and for many Poles it is an pointless waste of good money (I could well live on 10 quid a week for example at times in England (I mean buying food stuff)) - I still prefer to have my hair cut by a barber and with scissors mostly so I never economised on it
now I know what a buzz cut is - and no - I wouldn't like my hair this way (it's just next to shaving your head ain't it)