Because, we have a lifetime limit on uploads. I reached mine :(. It is not a huge amount! So, they are working on the problem, but in the meantime, I needed to upload other things, and so, made a duplicate account.
To see what your limit is, go to Attachments under your profile, the top bar graph will show you what you've uploaded and how much you've used, and yes, emails count as well. Links, however, do not count.
-Dacy