It's possible that Bp. Huonder actually believes that he is an advocate of Tradition. He does explain his defense of Tradition in the OP article. However, the SSPX evidently has not corrected Bp. Huonder; since the Neo-SSPX appears to have the same watered-down version of Tradition that Bp. Huonder has. It's not all Bp. Huonder's fault. The SSPX allowed him to move to the SSPX, and the current leadership of the SSPX, unfortunately, has the same mindset as Bp. Huonder.
The SSPX (leadership, mainly) has moved far, far away from the good example of Archbishop Lefebvre.