That's the argument of Tarek El Diwany. From the second last paragraph of the article:
Some purists dislike the way modern sharia finance is run. Tarek El Diwany, a consultant, says banks are devising loopholes to sell nominally sharia-compliant products that are essentially the same as any other. For 1,400 years Islamic finance has been based on mutual ownership and profit-sharing, he says. But most sharia deposits return a specified rate similar to interest, not a share of actual profits earned. He describes it as “blank-faced copy-catting”.
There could be some real differences between conventional and Sharia-based lending, but, no sarcasm, banks are great at moving around risks in ways non-finance people can hardly imagine and it would be a trivial exercise for them to move the chips around to make the Sharia stuff merely appear to be Sharia while still being conventional, using the mass of conventional investments as raw material, in a way that also is set up so it works 99% of the time but will in some manner catastrophically fail in a Black Swan [1] event because of the games they played with moving risks around until even their own computers don't really understand it anymore.
[1]: Though as Taleb says, is it really a "Black Swan" when it was really quite predictable all along, if you just reject their statistical framework and use something with more realistic fat tails?
It’s definitely possible, but the sharia bank would also have a contractual obligation to share in the loss. For something like a mortgage on a home, the title would belong to the sharia bank until the loan was paid off. Banking becomes extremely conservative in state of affairs.
In theory, strict rules like these should be extremely hard to game; in practice, banks and other financial institutions are a little too creative.
Seems like they need to have some inspector-scholars verify that there are no haram banking practices going on.
From my perspective, a "sharia bank" is an oxymoron. Muslims should be exclusively patronizing "sharia credit unions". Professional bankers are too clever by far to be obeying the spirit of the Muslim business laws. If there were doing it correctly, they would have zero non-Muslim customers, because sharia banking is fundamentally uncompetitive with non-Muslim banking in such a way that even academic macro-economists can prove it.
Some purists dislike the way modern sharia finance is run. Tarek El Diwany, a consultant, says banks are devising loopholes to sell nominally sharia-compliant products that are essentially the same as any other. For 1,400 years Islamic finance has been based on mutual ownership and profit-sharing, he says. But most sharia deposits return a specified rate similar to interest, not a share of actual profits earned. He describes it as “blank-faced copy-catting”.