It works. Non-comepetes are basically unenforceable regardless of state. They are just used to threaten and bluff. Telling them to fuck off shows you know they have no standing.
Even by the standard of what passes for legal advice on the internet, this is especially terrible advice. I also live in the Midwest and am currently sitting out a noncompete agreement (which, since it must be paid to be enforceable in my state, has been quite enjoyable).
Like you, I’m also not a lawyer, but I did engage the services of a firm when I left. My lawyer informed me in no uncertain terms that my noncompete agreement was enforceable and cited several cases where a) their firm took employers to court to have the agreements tossed and lost and b) unsuccessfully defended people who did what you did and were sued by their previous employer.
In general, “fuck off, sue me” usually isn’t a great legal strategy.