Mainly because it's the kind of bullshit statement that gets people talking about getting rid of measles and polio vaccines. I don't personally care about the covid vaccine anymore because its lost a lot of its virulence. However, measles was the number one childhood killer for a long time and it essentially vanished in the US after the vaccine. And its not triggering, the word "the jab" just sounds fucking stupid like calling a Les Paul a "Lester" or using the term guitfiddle.
And I'm a doctor and take care of some people who were old enough to have fucking polio! People quickly generalize shit in both directions.