There are legal systems which prevent convicted sex offenders from entering or re-entering certain professions. This is from a risk management point of view, and from this perspective football is fine as a career, he won't have unsupervised access to women and girls. What this thread is discussing is a moral objection to Evans returning to his job, because of the way footballers are lauded and treated as heroes by their fans, and the ridiculous pay it receives.
I don't think the justice system can get involved in the ethical side, because of the massive levels of subjectivity involved in deciding which types of very low risk employment are ruled out for reasons unrelated to risk of re-offending or risk of harm to others. Unfortunately that leaves the decision down to either the particular employer - and Sheffield United are clearly at least considering re-engaging Evans - or its overseeing body. Which in the case of football is run by men, and men who have been demonstrated to be taking very limited action to address misogyny, homophobia and racism. I have signed the petition because with the current situation as it is I feel it is entirely justified to make an example of Evans. Football needs to show its own repugnance - it needs to take a moral stance.
For what it's worth, denial is totally normal for offenders in Evans' situation, especially with the added element of being in the public eye. I would be wary of the genuineness of any admission at this stage. But he will be on the Sex Offender register and have to comply with its requirements, even after his sentence ends.