We show that for graph Laplacians $Delta_G$ on a connected locally finite simplicial undirected graph $G$ with countable infinite vertex set $V$ none of the operators $alpha,mathrm{Id}+betaDelta_G, alpha,betainmathbb{K},beta e 0$, generate a strongly continuous semigroup on $mathbb{K}^V$ when the latter is equipped with the product topology.