shows that a) laws do indeed get repealed in the US and b) reducing regulation may even increase the risk of chaos, not reduce it
The act did not ban securitization or buying derivatives. Even wiki can't find any justification for this argument beyond an unsourced 'cultural shift'.
And even if you read all those citations and didn't find them convincing (or found the cited counterarguments more convincing), then point a) above would still stand - claiming that regulations are never revised or repealed is an uninformed stance
As for your new cite, I'd say it's the arguments in favour that are most damning. They tend to eventually concede the point that G&S did not and would not ban the behaviour leading to the crisis; They just lament that their policy choices weren't implemented at the time or lament some 'cultural shift' with no evidence to substantiate it (IMHO, everyone looking could have seen the culture shifting at least a decade earlier).
Aside, the argument was never that regulations are never repealed - but that the natural overall direction is ever expanding regulation. This thread is arguably somewhat of a confirmation, since people are arguing for a regulation which had little to do with the crisis...
[0] "The perception is that the Glass-Steagall Act created a sense of accountability among investors within the financial management industry... Thus a cultural shift was certainly in order after its repeal regardless of the loopholes that existed prior."
This has no source, and violates wiki's ban on original research.