I'm not happy about it either, and I don't necessarily approve of the government's or airlines' ability to restrict these rights, but that's the way it is. When you buy a ticket, you agree to a contract that is nearly as impenetrable as a credit card agreement, and gives just as much power to the corporation. See, for example, the
United Airlines Contract of Carriage. You voluntarily sign over a whole lot of rights by engaging in commerce with an airline, before you ever deal with the TSA. And by the way, that Constitutional right you mentioned is granted to Congress, not individuals. Article I, Section 8 says: "The Congress shall have power ... To regulate Commerce with foreign Nations, and among the several States, and with the Indian Tribes." So whether the government ought to be involved, and whatever the intrinsic human rights questions, I don't see how there's a question of constitutionality.
I used the value-laden term "copping an attitude" because that's how any action standing up for your rights (if indeed they are rights you haven't signed away) will be interpreted and dealt with by the airlines. It sucks, but I don't think you can change it by anything you do at an airport. Given the amount of rights you simply don't have while travelling by air, it's totally different than dealing with ordinary police officers.
I don't like it either, but the battle can only be fought in the courts, Congress, and the executive branch, and it will be a hard one. Frankly, I think it would be easier to get a nationwide high speed rail system (as in, actually fast, not like the Acela) in place that could replace airlines. That is, it's nearly a hopeless cause. But I agree that the current situation sucks.