I don't know about where you live but I have not seen anyone with the flu thus far this year. There has been a lot of people with colds. Maybe it is a slow start or maybe people are better off without flu shots unless they have other serious health problems.
I haven't heard of anyone with the flu here on the Pacific coast. A couple of bad, long colds, but no flu.
I have a suspicion you're right. I'm 52, in good health, and I don't like injecting foreign substances into my body. I'm not going to do anything to weaken an immune system that's already working quite nicely. There are plenty of other nasty things besides flu that can take advantage of undefended territory.