Since you did not quote the part where I warned about that then I assume you did not read it:
You should be on the watch for their javascript changing though.
Wasn't that an edit ? Sorry if it wasn't and I overlooked it

There are plugins for browsers that will warn you if the javascript changes.
Yep, but that isn't blockchain.info anymore, that's blockchain.info + a plugin.
The source code as it stands now is very easy to read.
My mom still has issues with the concepts of copy and paste

With such a plugin I would consider it to be reasonably safe.
I do agree, but many people still think it's some kind of security silver bullet where they don't have to trust the operator since he "doesn't have access to your keys". Honestly, how much people do you think use some kind of JS verifier ?