I’m not a huge fan of Roger Lowenstein’s NYT Magazine piece on Jamie Dimon, which comes complete with a positively glowing cover photo. It seems altogether too sympathetic to the man—who is, it must be said, a good banker—while failing to make the point that we can’t regulate a banking system on the assumption that the biggest banks will always be run by good bankers.

Dimon gave Lowenstein a very impressive degree of access for this article and from a PR perspective that decision makes perfect sense. Dimon is a good bank CEO and can make a very credible case that he’s part of the solution rather than part of the problem. One can’t necessarily blame Dimon for taking the banker-bashing personally—but I think it’s fair to blame Lowenstein for failing to point out that Dimon’s “l’état, c’est moi” attitude is itself problematic. The problems with megabanks like JP Morgan are not problems that Dimon or anybody else can solve: they’re endemic to any bank with assets of $2 trillion and growing. Here’s Lowenstein, on Dimon:

He was adamant that government officials — he seemed to include President Obama — have been unfairly tarring all bankers indiscriminately. “It’s harmful, it’s unfair and it leads to bad policy,” he told me again and again. It’s a subject that makes him boil, because Dimon’s career has been all about being discriminating — about weighing this or that particular risk, sifting through the merits of this or that loan.

The point here, surely, is that government has to be indiscriminate when it comes to bank regulation. Yes, on a case-by-case basis, the government can play favorites—and indeed it did so, during the crisis, when it engineered the transfer of both Bear Stearns and Washington Mutual into Dimon’s safe pair of hands. But equally the government can’t soft-pedal its regulation of banks and bankers on the grounds that one particular banker happens to have come out of the crisis with his reputation for risk management largely intact.

Lowenstein continues:

There are, believe it or not, reasons for wanting banks to be big, including safety. A large bank with many loans is less prone to failure than, say, a bank in Texas that lends to only oil drillers. For related reasons, as a bank gets bigger, its credit will generally be stronger, its borrowing costs lower. But as Dimon points out, banking also suffers from diseconomies of scale, like the lack of attention to detail and the “hubris” that can undermine a large organization. Such sins are precisely what crippled Citigroup and A.I.G. Nonetheless, Dimon insists that for a bank that gets it right, the positives of consolidation are overwhelming. Since J. P. Morgan’s acquisition, in 2008, of Washington Mutual, each Chase branch spends $1 million less on overhead and technology than it did before.

This is too credulous. Yes, big banks are less prone to failure than small banks—but that just makes them more dangerous, from a systemic perspective. If a lender to Texan oil drillers goes bust, the systemic repercussions are de minimis. If Citigroup or AIG goes bust, the whole world feels the impact. If a lot of small banks all make very similar loans to very similar people, then they can collectively approach the systemic impact of one large bank—but even then they won’t be so interconnected and so international that taxpayers are essentially forced to bail them out.

And I really don’t know what to make of that $1 million a year figure. If it’s true, it implies that Chase was a very inefficient retail bank and that Dimon was not half as good at running it as he’d like us to think. It also means that if small banks and credit unions found it hard to compete with Chase before, they’ll find it impossible to compete with Chase now. But I do wish I knew where the number came from, because I have to admit I’m suspicious.

Felix Salmon is an Audit contributor. He's also the finance blogger for Reuters; this post can also be found at Reuters.com.