It's probably a bit of both from what I've seen of how Americans tend to react to their government doing things (online anyways).
The US's quagmire of incoherent laws and many jurisdictions seems to be a bad combination of:
* Apathetic voters that are raised on a media diet of "big government bad", which impedes any regulations on a federal level. (Note that this is irrespective on if the voters actually want a small government, it's what they're led to believe.)
* Politicians that don't like to give up power; there's an unusual desire for local/state US officials to claim responsibility and get very pissy when the federal government steps in with a standardized solution. This is very unusual compared to other countries; punting responsibilities to local officials in other countries is generally seen as a way for politicians to abdicate responsibility by letting it die in micromanagement and overworked administrative workers and isn't popular to do anymore these days. (This is also a two way street, where federal US lawmakers can abdicate making any legislation that isn't extremely popular by just punting it down to the states, even if they have legal majorities.)
* The US has a court system that overly favors case law rather than actual law. Laws in the US are permitted to be painfully underdefined since there's an assumption that the courts will work out all the finer details. It's an old system more designed around the days of bad infrastructure across large distances (like well, the British Empire, which it's copied from). It's meant to empower the judicial branch to be able to make the snap decision even if there's not directly a law on the books (yet) or if a law hasn't actually reached the judiciary in question. The result is that you end up with a bunch of different judiciaries, each with their own slightly different rules. It also encourages other bad behavior like jurisdiction shopping where people will try to find the judiciary most favorable to them, crafting "the perfect case" to get a case law on the books the way you want it to get judges to override similar cases and so on and so forth - in other countries, what the supreme court judges doesn't have nearly the same lasting impact that a decision in the US has.
* And finally, the entire system is effectively kept stuck in place because lobbyists like it this way; if they want to kill regulation, they just get some states to pass on it and then hem and haw at the notion of a federal regulation. Politicians keep it in place on their own, lobbyists provide them the grease/excuse to keep doing it. (And those lobbyists these days also have increasing amounts of ownership over the US media, so the rethoric about voters not liking big government regulations is reinforced by them as well.)
It didn't end up this way on purpose; the historical reasons for this are mostly untied from lobby interests (which is mostly just "the US is the size of a continent in width", "states didn't actually work together that much at first" and "the US copied shit from the British Empire"), but they're kept this way by lobby interests.