Final answer:
The Irish penitential system gained popularity due to its emphasis on the humanity of Christ and the idea of God understanding human suffering. It also provided individuals with the opportunity to confess sins and seek absolution through acts of penance.
Step-by-step explanation:
The attributes of the Irish penitential system that made it more popular included its emphasis on the humanity of Christ and the idea that God understands the pain and difficulty of being human. This new devotional style quickly spread throughout western Europe through the rise of religious orders like the Franciscans. Additionally, the penitential system offered individuals the opportunity to confess their sins, receive absolution, and engage in acts of penance to atone for their actions and seek salvation.