Ultimately, I think the only way to kill the RSA key exchange is via a protocol revision, which is exactly what they've done in TLS 1.3. Sure, it will take a few years, but it will happen eventually.
I think banks like the RSA key exchange because it allows them to deploy transparent TLS traffic decryption via private key sharing.
It's amazing how strong a motivation a grade or ranking can sometimes be. We saw this a lot with EFF's privacy practices report
https://www.eff.org/who-has-your-back-government-data-reques...
where companies were sometimes willing to make real changes to earn an extra star.
> I think banks like the RSA key exchange because it allows them to deploy transparent TLS traffic decryption via private key sharing.
Oh yeah, that was something they complained about a lot with mandatory PFS in the TLSWG. :-(
Why do they need this for their consumer-facing sites, though? The theory over in the working group was about monitoring activities of bank employees on third-party web sites (I thought), rather than about monitoring activities of bank customers on the bank's own web site.
I just noticed two days ago that my bank, for example, uses an RSA key exchange and I was kind of dismayed about the non-forward-secret sessions. But I don't know what I could tell them as a customer that would make them care about this problem. (I don't think my theoretical knowledge of why their key exchange method is bad will really help, compared to some kind of industry or governmental guidance that says "this technology is obsolete and everyone should stop using it", or, even better, "this technology is obsolete and banks should stop using it".)