Absolutely.
Having served your time most definitely does not allow you to follow a career path of your choosing, even if it was your previous career. It doesn't stop you following another line of work, but if you were a professional in the true sense of the word you'd most likely find yourself bounced out of your guild or association (most of which have codes of conduct for their members which preclude criminal behaviour). The PFA doesn't seem to have a code of conduct, more's the pity, but regardless Evans wants to follow a career in which he represents, in public, the people who pay his wages. Many of those people don't like the idea of that, given the nature of his offence.
There's nothing in law to stop a club employing him, but there's also no legal obligation for anyone to do so. The law also protects the right of free speech and many (including commercial sponsors) have clearly exercised that with regard to Evans.
He's entitled to look for work as a professional footballer, and as a supporter I'm entitled to say that I wouldn't want a man like that wearing my club's shirt. I'm not asking for him to be hung, drawn and quartered - he can play elsewhere if he can find a team that can abide him, or he can look for a different career and rebuild his life quietly as do many other ex-offenders.