Links to vs. is linked to

In the below sentences, "links to" seems odd to me.

Since verb 'link' is a transitive verb, it is supposed to be used like 'is linked to.'

Can you tell me whether I'm right or not?

The eye is the gateway, the first connection between man and word. Yet sound is the foundation of reading, as is fitting for a species that developed complex oral communications long before writing was born. A child must be able to understand the sounds of language, from syllables to phonemes, the smallest units of sounds in speech, before she can read. This skill is so crucial that a low capacity to discriminate phonemes in infants links to later difficulties in learning to read.