Or is it that the victims pest warning system is currently winning the biological arms race, in which case how are mosquitoes able to successfully reproduce? Or is it that mosquitoes have evolved such that their spawning numbers offset the difficulty they have biting?
Biology is hard.
It’s a common rhetorical shortcut to anthropomorphize evolution. Doing so doesn’t necessarily indicate that the writer doesn’t understand how evolution works. It’s just cumbersome to repeat an explanation of random mutation and natural selection in every discussion of evolved trait.
Neither creatures nor evolution get to “decide” to develop a trait but, as countless evolutionary arms races show, useful traits and refinements do tend to happen in a way that evokes a sense of conscious decision making.