Well I do not consider it that dangerous. I believe that it would be inconvenient to have No as default. If you do not like it, you can at least setup remote recycle bin.
tenfourzero
DefaultOption When Overwriting File
When I'm asked to confirm that I want to over-write a file on upload, the "YES" option is highlighted.
This seems a little dangerous, seems sensible to have "NO" or "CANCEL" as the default?