I am confused by what appears to be an assertion that Jimmy John's has a legitimate concern that their minimum-wage-earning food service employees might leave to start a competing national sandwich chain.
Doesn't mean blanket non-compete is fair, but to completely dismiss the OPs point it at best naive.
My opinion is that Jimmy Johns is in fact not concerned that their employes will start competing firms. Rather, they'd like to minimize employee turnover, which, unlike local sandwich business starts, is a metric they actually probably do track. And one vehicle they've found for minimizing turnover is in tricking their employees into believing they have fewer alternative jobs available than they actually do.
The blanket way OP has been dismissed really has to do with the rustled jimmies about the fairness of the policy and does not reflect well on the quality of the replies.
The argument that asking employees to sign a non-compete is somehow unethical, yet getting a low-wage job to learn how to run a competing business is not unethical is moot and completely subjective.
It's certain that Jimmy John's line-worker can't start a 2,000 store chain, but they could run off with some of the catering business.
I generally agree with you that limiting future employment is generally not a good thing, although I'm not convinced getting rid of non-competes in minimum wage jobs would materially affect wages. At most, it might prevent someone from taking a manager position at Subway, but I don't think it is going to raise the overall wages of restaurant workers.
The idea that Jimmy Johns could expect the right to bind minimum-wage-earning food service workers with a noncompete is verkakte. Even in circumstances where employees are given access to trade secrets and client rolodexes, noncompete agreements are difficult to enforce and almost invariably slashed to bits by courts when they survive at all.
Obviously, Jimmy Johns will not prevail in enforcing a noncompete on a minimum-wage employee. What they're doing is simply intimidating their own workers, probably based on some simple calculation about the impact their bogus noncompete will have on employee turnover, which is a metric every at-scale retail business optimizes for.
It is easy to devise logically-consistent reasons Jimmy Johns would want to bind their employees with anti-competitive contracts. Such arguments more or less beg the question.