I essentially have to get the flu shot because I work in healthcare. If I don't, I'm forced to wear a mask for the entire flu season.
I get the flu shot because I feel it's important that I do my part to keep myself safe as well as the individuals I care for. There are a few people that work with me that wear the mask, but none of them are particularly bright individuals and they don't exactly have the best reasons for refusing to get the shot. One thing I've noticed is that I've never seen a doctor wearing a mask during flu season.
If you have an egg allergy, a history of Guillain-Barre Syndrome, or a history of serious adverse reactions to vaccines, then by all means don't get the flu shot. If you don't fall into those categories, your reasons for why you shouldn't get it probably aren't all that good.