I have been hit with "for real" influenza twice in this lifetime. It was a week of absolute misery both times.
I get my flu shot tomorrow. Even if it's only marginally effective it's a better bet than not getting the vaccine. At least that's how I see it.
(I don't love big pharma by any means, but am also not willing to cut my nose to spite my face.)
Point of fact: the condition of one's immune systems has very little relationship to who gets the flu or how ill that person might become. Indeed, the influenza is noted for felling the most vigorous and healthy among us because of the counter-attacks our immune systems launch against the virus.
If you have any interest in learning how the flu attacks, why those infected feel fine one night and wake up feeling like a truck hit them, and why the 1918 flu was so deadly, I can highly recommend, "The Great Influenza: the Story of the Deadliest Pandemic in History" by John M. Barry. There's probably a copy at your local library. It is a spectacularly well researched, fascinating account of how this pandemic unfolded.
After reading it I have never gone through a flu season being armed (pun intended) with a fresh vaccine.