Problem

Per the doc of Axis.set_ticks:

        **kwargs
            `.Text` properties for the labels. These take effect only if you
            pass *labels*. In other cases, please use `~.Axes.tick_params`.

This means that in e.g. ax.set_xticks([0, 1], xticklabels=["a", "b"]), the incorrect xticklabels silently do nothing; they are not even validated (because labels has not been passed).

Proposed solution

We should at least check that kwargs are valid Text properties in all cases; we could even consider making any kwargs an error if labels is not set.