IBanking didn't even come into its heyday until the 70s/80s. Of course the new hotshots wanted to get government into their pocket, but it's not like there was a modern IBanking industry in the 40s, 50s, 60s, clamoring at the bit.
This is way more than taking a company public, it has to do with the way financing is structured and supplied to businesses and investors. Most retail banks were not making the type of investments that Glass Steagall would have prohibited. BOA is one exception of course but they have a Retail and an IBanking arm.. the two could split ways and carry on business as usual, nothing would change.
The crux of the problem is, as you seem to allude to, that government is in bed with the industry and is all to happy to help them in their shenannegans. Which do not consist of outright demolishing the economy so much as supplying the means by which unprofitable businesses stay in business and run profitable competitors out of business. Well that to me sounds less like IBanking and more like the gist of what the government does already.
Don't misunderstand- I'm not in favor of deregulating so that assholes like JPM and GS can continue to play their games. I'm in favor of deregulating so that tainted companies don't get access to federally backed financing that the rest of us have to pay for. But to blame GS for the recession is wrong- GS is to blame for the boom that made the recession an inevitability. congress' idea of a "fix" is to figure out a way to keep those booms going, without the side effects. And this isn't possible. Until congress and the average person accept that reality, our recessions will be worse than a normal business cycle. I believe things will actually get worse in the coming years because the rest of the world is catching up to the west in living standards and is directly competing rather than complacently subsidizing western lifestyles.
The main purvue of the SEC is to prevent securities fraud, not stop overleveraging. And it has done a fairly good job of the former- despite Madoff and other high profile pyramid schemes there are far fewer of these than there were prior to the SEC, AND the SEC can recover money for the investors. But the SEC was & is powerless to prevent the type of excesses that got us to where we are. I am extremely worried about the effects of a government regulator that, in effect, regulates drive and ambition. It seems like the government is a lot more interested in propping up the status quo of a marginally well off underclass rather than promoting a free market and the social & economic mobility that comes with it