Ambystoma velasci is actually classified as "Least Concern" by the IUCN

https://www.iucnredlist.org/species/62130287/53974804

I'm not arguing one is more important than the other but only one of them is critically endangered and only one of them is a powerful cultural indigenous symbol.

Ambystoma velasci is also an "actual" salamander. The unique thing about the axolotl is that it never goes to the stage where it leaves the water. It is the only salamander species known to do this.