The quoted material is important, because people expect to be able to retrace the conversation within the single message. Technical (and also nontechnical) exchanges often consist of a dozen messages about a particular topic spread over weeks or sometimes months, where at almost each step you want to go back in the conversation to look at details of the previous discussion or to refresh your memory. Outlook users are used to doing so by scrolling through the message. They are generally not used to having to bring up the correct previous message -- Outlook also doesn't have a great UX for that.
> The quoted material is important, because people expect to be able to retrace the conversation within the single message.
Given the proliferation of rendering a thread of messages and showing them as a conversation (i.e., conversation view), reading the quoted material within the same message is not really necessary.
> Technical (and also nontechnical) exchanges often consist of a dozen messages about a particular topic spread over weeks or sometimes months, where at almost each step you want to go back in the conversation to look at details of the previous discussion or to refresh your memory.
While I have seen this done in threads where people follow the conventions of a typical mailing list or usenet newsgroup by replying inline and quoting only parts of the text they're responding to, I have not seen the equivalent in a threaded conversation in outlook. And, as you note:
> Outlook also doesn't have a great UX for that.
While they have addressed the UX issue to some extent with the conversation view, it still doesn't really lend itself to easily following the discussion amongst multiple people due to the fact that they don't typically use different subthreads under the same email chain.
