the finances alone would likely have been more than enough to keep him from getting the final job offer and security clearance. He would have been too vulnerable to bribery and too susceptible to making policy decisions that would improve his personal financial situation.
Forget Kushner, this sentence is more germanely applied to Donald Trump.
Trump does technically own five buildings in NYC, but they are not worth a billion dollars much less the 8.5 billion he claims to be worth. He also has partial stakes in several other buildings. What he has a TON of are licensing deals, where he lends his name to another developer who builds and operates a building and uses the Trump "luxury brand" to draw clients. Many of these operations are overseas. In places like Iran and Saudi Arabia and various former Soviet republics. He's literally doing business with foreign governments, while also setting US foreign policy. How can we be expected not to ask the obvious question, "Is this foreign policy change what Trump thinks is best for the country, or is it what Trump thinks is best for the Trump business empire?"
The brand licensing is a sticky subject. On the one hand, Trump needs to claim ownership of those buildings that bear his name to support his curated self-image as a real estate developer. Those same buildings are drawing profits from foreign governments, who send their delegations there with promises of having an audience with the POTUS, which is why so many people are crying "emoluments violate the Constitution!" for the money he makes from these properties. On the other hand, he doesn't actually own these buildings and most of their profits flow to other people, since he's basically a PR brand and not an owner or a manager. Trump could easily defend himself from the "emolument!" criticism if he just publicly admitted that he doesn't own or operate any of these buildings, or really have any stake in them at all except for the quarterly retainer he gets for leasing his name. Except that admission would undercut his entire PR empire, which is built on convincing people that he's a real estate investor. He's stuck.
And because he doesn't actually own any equity in all of these buildings, his net worth isn't actually very high. His income is high, because he gets all of these licensing payments, but they are cash paid to him instead of assets, and he spends it on things like gold-plating his apartment and painting his name on helicopters, because he feels he needs to support a public image of success. Without any actual assets, his net worth is based on the net present value of these income streams. He (or his accountant) seems to be assuming that today's low interest rates justify an assumed super low interest payment, which means that $100m of annual revenue is "worth" billions dollars, because that's the amount you'd need to have invested today to generate that income stream.
Kushner is still trying to do what Trump has long since given up on doing: borrowing money to buy buildings. He's up to his eyeballs in debt and can't afford to make the interest payments, which is exactly how Trump kept going bankrupt. The whole thing is a sham, and these people are now in charge of our economy? Methinks we're doomed.