Heh -- it kind of makes sense since it's really meant to be used via NNTP. (That's the whole raison d'être for GMANE.)
Yeah, I get that, but the HTML interface is so awful I think we'd all be better off if we just used Gnus to read it.
Yes, but at least it bothered to parse the email and display it? The original URL seems to have very nearly just echoed the raw MIME message into an HTML page.
FWIW, I find Gmane much easier to use than Google Groups. It doesn't take ages to asynchronously load via JS and then hijack common browser behavior or make it harder to use the browsers history mechanism to return to where the tab was closed. Gmane's servers are slow, but the interface is much easier to use because it's a simple design.