"There's always someone who speaks at great length about finance while being clueless about the subject. [...] And no, Glass-Steagall doesn't have anything to do with offering interest on checking accounts."

snicker Try section 11(b), which was implemented as the infamous "Regulation Q". Normally I'd refrain from mocking someone for an innocent error on a side point, but the irony here is just too delicious. Even if you are completely clueless about Glass-Steagall, this is discussed in detail in the Wikipedia page about it. It takes a special person to know nothing about a subject, not even do the 20 seconds of research needed to confirm a claim, and still feel like insulting other people for their factual claims is a good idea.

(As for your substantive point... No. Countrywide, for example, was not taking risks on the "investment side" under the meaning of Glass-Steagall; they didn't even have an investment side. The core damage there was a pure-play retail bank making crap loans, and Glass-Steagall says that's awesome. You're arguing against the repeal of a regulation which never existed. Might have been a good one though.)