It's a real shame Puerto Rico is plagued with corruption resulting in poor infrastructure.
The sad thing is most of the debt was post the 1996 US tax change when the US Government (President Clinton + Republican Congress) decided to phase out the pharma/manufacturing special deal for Puerto Rico. The government of PR basically didn't do much to try to replace that industry until 2006 when it actually left, then started massive borrowing to make up for the shortfall (operating expenses, not capital spending), then 2008 financial problems happened and it kept compounding. The hurricane was comparatively minor.
PR people also engaged in protests bordering on terrorism (and some in outright terrorism) in the US or against US entities in the 20th century, and this colored the US-PR relationship. Most recently the Puerto Rico Vieques range protests caused the entire US military to basically pull out of PR, costing 6000+ jobs.
In 2012 they put in place a bunch of new tax credits for businesses and individuals, and enhanced them in 2017. It may be too little, too late, but combined with privatizing the power grid and a bunch of other capital investment, it's a better outlook today than it was in 2006. The ~$70B in debt is a big problem but it can be restructured; what matters the most is that the economy actually works so there is some surplus to service and pay down the debt.
Corrupt local politicians.
FEMA/USG response was weak in the first month, but part of that was just the genuine logistical difficulty of supporting Puerto Rico vs. a contiguous state. The scale of the USG response from December 2017 onward has been beyond what I would have expected, and probably pushing the limits of statutory authority for political reasons.
Puerto Rico is a colony of the United States, and the purpose of a colonial relationship isn't for the imperial power to aid the colony. That's sometimes a side effect, but the intent is for benefit to flow the other way.
If Puerto Rico were part of, rather than a territory subject to, the United States, they would have representation in both houses of Congress and in the Electoral College.
If anyone wants more info on the topic, John Oliver has a great, 13-min segment on U.S. territories along with the clearly-evil justifications for their situation. Wait till yall see the Supreme Court ruling. It should get way more attention in media discussions on this topic. His finale with America's Got Talent contestant is also an epic counter to that.
No relationship is one sided - it takes two to make it a relationship.
The US doesn't need Puerto Rico - Puerto Rico needs the US.
The US didn't “find” it, it took it by force.
EDIT: From another colonial power. I’m not sure Spain is really in the market for a Carribean colony right now, so it might not be that easy for the US to walk away and leave PR in its pre-US position.
That 1812 Constitution of Spain was a product of the Napoleonic wars and seems to have been basically ignored everywhere but Iberia-proper. So really, PR has never had proper representation to its colonial rulers. And technically PR has had a non-voting rep. in the US house of representatives since 1901.
Well, we do let them have one non-voting representative in the House (similar to D.C. and other territories.)
But, yes, it was a deliberate choice in the Constitution that the capital district would be a subject territory, a decision which was partially walked back only fairly recently by the 23rd Amendment.
They are U.S. citizens. It is a U.S. territory. They are required to follow U.S. Federal law, yet do not have representation within the U.S. government. Even if they were not U.S. citizens, since they are not autonomous and allowed to govern themselves entirely, the U.S. has some responsibility over any situation Puerto Rico finds itself in.
If you think they should be paying income taxes, tell your congressperson to stop dragging their feet and respond to the requests for statehood Puerto Rico's government has made multiple times.