Because it's not necessary.Yeah and why wouldn't we want to eliminate cold? What's next? If you have an itch are you going to scratch it?
The last time I had a flu vaccine I had an adverse reaction and was in a children's hospital for a month almost completely paralyzed.
It's not "safe" in any way, in fact, it's more like playing Russian Roulette.
I say suck it up and deal with it. Save the vaccine for something like IDK, seriously life-threatening. Or do what you want, I don't really care.