Why is this in forum suggestions? I'm posting this from my iPhone and it works fine.
I just think that it's too much work. Would you rather have this than new cards and features? Even if it's not as big a change as making an app, it's probably still hard or will take a long time. It will most likely still be hard to use, and as you mentioned, uglier. I personally doubt that many people will use the mobile version. IMO this is just a waste of time and effort, but I might be wrong. Of course I'm not against it if it proves to be useful, I just think it won't be used by many people, and therefore is unnecessary.
Btw, I used to really want an app or mobile version of Elements. But now that I think about it, do we really need something like that?