dirtbiker - Yes, but these holidays also contribute overall to the economy and are important in a consumer based economy so in a left handed way are actually necessary. The "new" Black Friday phenomena is a good example of that and it does extend to outside the US even here to Hungary. They have no clue what Thanksgiving is but they are very eager for Black Friday. The rest of the Americanized commercial holidays have so far, not taken on.
I also worked with a number of other ethnicities but in the military it was actually fairly rare in the years I was in to see anyone else volunteering. So, generally I was the only one I knew of doing that. I did a lot of moonlighting as a Medical Technologist when I was stationed in the US and worked at civilian hospitals on the night shift so I often took holidays there as well. It made little difference to me but I do know there is a distinct increase in craziness on holidays, particularly on New Years Eve and Christmas and I could always look forward to having hellaciously busy shifts those nights with a lot of toxicology screens, blood alcohol levels, and blood transfusions all of which back in the day were extremely labor intensive in the laboratory. I can also personally attest that Full Moon nights are crazy ones as well. When I was going to University to get my BS (I had grandfathered in as a Medical Technologist) I worked night shifts and went to school in the daytime (this was after serving 15 years as a Sergeant in the Army as a Senior NCOIC of laboratories) I was not able to get a lot of sleep. The lab permitted sleeping on shift but on those holidays and Full Moon nights it was hopeless to even think about it. Normally, I did homework or wrote papers but you could depend on it being a busy night on those days. So, no homework and no sleep. Later after I graduated and became the Laboratory Director at my hospital we had no night shift (not my choice but for budgetary reasons) so all of us pulled on-call duty to cover nights. I always took the holidays and Friday night every week. Not too long after I got involuntarily recalled to active duty in the Army for another 18 years from that job until I reached my maximum age of service and retired. I had repeatedly attempted to retire which was categorically refused as I was "mission essential". I was able to get a PhD out of it though which put me into the essential position doing sensitive classified research. I still volunteered even then but I was in the Field Officer of the Day role by then which was a weekly duty so harder to arrange for holidays. This was when I did the ski patroller thing for 20 years. But, I recall those earlier days sometimes fondly.