Read 1984 again if forgot why.

lol, there's layers of irony in this line

Ah, you mean the book about a prescriptivist policy of grammar coming top-down from government, that one?

And how the way that people rebelled was intentionally misuse of the rules in a "you didn't say I couldn't use it this way!", a form of descriptivism

Read 1984, if forget why

It's not a formal context, it's very obviously written in a breezy and casual style, where attention-grabbing is more important than formalities

The call-response format is short-long in stressing, which gives it a PUNCH that "fewer" would lose as well

1 2 3 4 5 6 1 2 3 4 5 6

Feels more punchy than

1 2 3 4 5 6 7 1 2 3 4 5 6 7

Also, it's not a recruitment poster, it's a political advocacy poster.