more likely to result in a crash than drinking.

In both cases a person is choosing to do something that they know will put themselves and others In harms way and they do it anyway. And the texter is even wilfully doing it in real-time while in a clear sate of mind.

But in one instance, people want to come down near maximally punitive on them and with the other, almost everyone does it (texting/driving) and rarely insist on harsh punishments.