Did Bali M surrender out of devotion or fear of dishonor?

In the pastime of Bali mahraja, it is very clearly visible how he is showing full surrender to Krishna, how he is feeling lowly, how he is glorifying the lord for his mercy etc. One thing however seems to be quite strange… In SB-8.22.2 and 3 when Bali maharaja is asking Lord to place his lotus feet on his head, he is giving reason that Bali is ‘fearful of defamation’ or ‘he can not allow his promise to go false’. According to the teachings of our acaryas a vaisnava simply acts as a puppet in the hands of the lord; he does not fear his own defamation (ex. Bhisma, Gopis, brahmana patnis).