I think there is a possible fix for this issue that won't put grandma's banking account at any greater risk. Put the requested level of security in the URL. So if the resource is httpq:// (or whatever) it means that we don't care if we are subject to MITM attacks and self signed certs are OK. Then when grandma goes to a https;// site and the identity of the site is questionable we can forbid the connection entirely. She could use the httpq:// form if she wanted but the bank could forbid that from their end by simply not accepting such connections (it would likely be implemented as a separate port). Other sites that are willing to trust their user's judgment would just allow both connections.
The root problem here is that the current system does not accurately take into account the intent of either the user or the provider. So the browser can not be entirely sure and then has to ask obscure/awkward questions after the fact.
Edit: Dunno if there is an easy way for a bank to stop someone from deliberately switching the URL to httpq:// in a MITM situation. So the intent would only be accurately represented for the user sometimes.
I think there is a possible fix for this issue that won't put grandma's banking account at any greater risk. Put the requested level of security in the URL. So if the resource is httpq:// (or whatever) it means that we don't care if we are subject to MITM attacks and self signed certs are OK. Then when grandma goes to a https;// site and the identity of the site is questionable we can forbid the connection entirely. She could use the httpq:// form if she wanted but the bank could forbid that from their end by simply not accepting such connections (it would likely be implemented as a separate port). Other sites that are willing to trust their user's judgment would just allow both connections.
The root problem here is that the current system does not accurately take into account the intent of either the user or the provider. So the browser can not be entirely sure and then has to ask obscure/awkward questions after the fact.
Edit: Dunno if there is an easy way for a bank to stop someone from deliberately switching the URL to httpq:// in a MITM situation. So the intent would only be accurately represented for the user sometimes.