I think this is really an area where the states should decide, and if they have no interest in protecting their citizens (or visitors) then so be it.
Look, if I am in Tennessee or South Dakota or Louisiana or Mississippi, I assume that the state government has absolutely no money and regulates absolutely nothing. if I decide to go on a carnival ride in one of these states (or frankly any GOP state) then I assume that no one has ever looked at anything at anytime beyond "what is the minimum we can do to keep this thing working."
(As an aside, this also is my assumption if I am anywhere outside of the U.S. Anyone who decides to go to Iraq hiking might get abducted. That is just how it is. I don't know anyone whose daughter or son goes to Pakistan and gets jailed or kidnapped says, "This is outrageous!" You are sending your kid (or your kid is sending herself) into the Wild West. American laws don't apply and American norms do not apply - that is part of the "beauty" being sought and with that comes the attendant danger.)
The proposal for federal intervention in safety regulations makes sense when you are discussing factory workers who need to have a job to survive -- yes, if my only choice to live and feed my family is to work at the Triangle Shirtwaist factory, then it should probably have a working fire extinguisher.
But no one has to go on a factory ride. No one reasonably assumes, "Well, that guy with 4 teeth almost certainly has made sure this ride (which goes 400 feet in the air) is safe." So giving the federal government power to regulate rides in "red" states is just another situation in which red states can tell their citizens that they are a low tax state and then shift the burden of protecting their citizens to the federal government (i.e., to the blue state residents who pay more into the government than they get back).
If the state of Kansas wants someone to get decapitated on a thrill ride, then that is a cost of living in Kansas. You pay $200 less in taxes each year, and when your kid goes on a water slide, he may end up dead. If you want better services, pay more in taxes. If not, then there is a cost.
When you go visit New Orleans on a busy weekend, it is amazing how you immediately get the vibe that a lot of illegal activity is occurring, but the powers that be really do not care. It will either occur or not, and maybe someone gets hurt and maybe someone does not. That is the bargain you get with NO. I have never been on Bourbon Street for over 40 minutes without seeing a bouncer throw a guy into the street and continue after him and beat him ala Gene Hackman in "Unforgiven"." That is part of the bargain.