I believe prongs are usually short enough to make it difficult to injure yourself this way unless you are really trying, but with some other long metal thing it could be really bad.
The only negative is the plug is physically larger than plugs used in other countries. This makes them take up more space in a bag/backpack. And it’s harder to cram lots of sockets into a small space like a power strip.
German plugs are almost as safe electrically, and hurt less when trodden upon.