Avidius stayed silent, bidding his time until he knew he was strong enough to repress his oppressors without having a backlash that would lead to his death.
When he got to the position of an Emperor, the highest position one could attain amongst the human kind, he had the option of paying back those that offended him, looked down on him.
He could take his personal revenge on them without being questioned by anybody, but he did not do that.
What prompted him to become the Emperor in the first place is because he had the desire to protect the people, to see to it that they never have to suffer unjustly ever again.
The people that bullied him, looked down on him. They also belong to that group of people he vowed to protect.
Avidius had to let go of his personal vendetta in exchange for keeping to his own words.
