So the Bateman Horn conjecture asserts for any irreducible $f_1(x), f_2(x), \ldots, f_k(x)\in \Bbb{Z}[x]$, where $f_1(x)f_2(x)\cdots f_k(x)$ has no fixed divisor, there exist infinitely many $n\in \Bbb{Z}$ such that $f_1(n), f_2(n), \ldots, f_k(n)$ are all simultaneously primes in $\Bbb{Z}$, and in fact predicts a specific asymptotic distribution for them.
Now I read somewhere that an analogous conjecture is false, replacing $\Bbb{Z}$ with $\Bbb{F_q}[t]$ for any finite field $\Bbb{F_q}$.
Could someone explain why this is true? I've seen a counterexample polynomial before, but I wasn't able to convince myself of its necessary compositeness. Perhaps I just missed something simple