I disagree. You can do what you want with your money, but when society decides to subsidize some activity (example contributing to a retirement account) with a tax break, then it is also reasonable to put some kind of limit on how much of that is willing to be subsidized. Are you saying it is nobody's business how much you put in your IRA, so you should be able to contribute above the current $5500 limit?
I think the abusive valuation that allows private equity folks to contribute restricted stock at supposedly near zero and then end up with millions in a tax free account should be prohibited. Likewise I think it's reasonable to decide that the favorable tax treatment to encourage low income workers to contribute to their savings will phase out at some income level. Putting a cap on retirement savings above which future contributions are not given tax breaks is logically the same as many other phase outs in the tax code. You may agree or disagree with the laws, but there's nothing fundamentally different about this limit.
None of these plans are saying you cannot have more than X saved. Only that if you have more than X saved then you no longer qualify for tax deductible treatment on further contributions.